diff --git a/ChangeLog b/ChangeLog
index f5169a820..5aa2b6522 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -11,6 +11,26 @@
 	* Added strings to translate and cleaned up the template to send
 	HTML mails instead of text/plain.
 
+2012-07-10  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
+
+	* SoObjects/Appointments/SOGoAppointmentFolder.m
+	(-davNotifyOnPersonalModifications)
+	(-setDavNotifyOnPersonalModifications:)
+	(-davNotifyOnExternalModifications)
+	(-setDavNotifyOnExternalModifications:)
+	(-davNotifyUserOnPersonalModifications)
+	(-setDavNotifyUserOnPersonalModifications:)
+	(-davNotifiedUserOnPersonalModifications)
+	(-setDavNotifiedUserOnPersonalModifications:): new dav accessors.
+
+
+	* SoObjects/SOGo/SOGoObject.m (-davBooleanForResult:): new method
+	that returns a valid DAV boolean from a BOOL.
+	(-isValidDAVBoolean:): new method that validates the value as a
+	DAV boolean.
+	(-resultForDAVBoolean:): new method that returns a BOOL from a DAV
+	boolean.
+
 2012-07-09  Ludovic Marcotte <lmarcotte@inverse.ca>
 
 	* Dropped old templates (SOGoAptMailDeletionReceipt.wox
diff --git a/SoObjects/Appointments/SOGoAppointmentFolder.m b/SoObjects/Appointments/SOGoAppointmentFolder.m
index 864d0ec26..29a64b77b 100644
--- a/SoObjects/Appointments/SOGoAppointmentFolder.m
+++ b/SoObjects/Appointments/SOGoAppointmentFolder.m
@@ -455,7 +455,7 @@ static NSNumber *sharedYes = nil;
 // We MUST keep the 'NO' value here, because we will always
 // fallback to the domain defaults otherwise.
 //
-- (BOOL) _setNotificationValue: (BOOL) b
+- (void) _setNotificationValue: (BOOL) b
                         forKey: (NSString *) theKey
 {
   [self setFolderPropertyValue: [NSNumber numberWithBool: b]
@@ -1005,7 +1005,9 @@ firstInstanceCalendarDateRange: (NGCalendarDateRange *) fir
   rules = [cycleinfo objectForKey: @"rules"];
   exRules = [cycleinfo objectForKey: @"exRules"];
   exDates = [cycleinfo objectForKey: @"exDates"];
-  eventTimeZone = allDayTimeZone = tz = nil;
+  eventTimeZone = nil;
+  allDayTimeZone = nil;
+  tz = nil;
 
   row = [self fixupRecord: theRecord];
   [row removeObjectForKey: @"c_cycleinfo"];
@@ -1062,7 +1064,9 @@ firstInstanceCalendarDateRange: (NGCalendarDateRange *) fir
                     }
                 }
 
-              tz = eventTimeZone? eventTimeZone : allDayTimeZone;
+#warning this code is ugly: we should not mix objects with different types as\
+  it reduces readability
+              tz = eventTimeZone ? eventTimeZone : allDayTimeZone;
               if (tz)
                 {
                   // Adjust the exception dates
@@ -2250,28 +2254,18 @@ firstInstanceCalendarDateRange: (NGCalendarDateRange *) fir
 
 - (NSString *) davCalendarShowAlarms
 {
-  NSString *boolean;
-
-  if ([self showCalendarAlarms])
-    boolean = @"true";
-  else
-    boolean = @"false";
-
-  return boolean;
+  return [self davBooleanForResult: [self showCalendarAlarms]];
 }
 
 - (NSException *) setDavCalendarShowAlarms: (id) newBoolean
 {
   NSException *error;
 
-  error = nil;
-
-  if ([newBoolean isEqualToString: @"true"]
-      || [newBoolean isEqualToString: @"1"])
-    [self setShowCalendarAlarms: YES];
-  else if ([newBoolean isEqualToString: @"false"]
-           || [newBoolean isEqualToString: @"0"])
-    [self setShowCalendarAlarms: NO];
+  if ([self isValidDAVBoolean: newBoolean])
+    {
+      [self setShowCalendarAlarms: [self resultForDAVBoolean: newBoolean]];
+      error = nil;
+    }
   else
     error = [NSException exceptionWithHTTPStatus: 400
                                           reason: @"Bad boolean value."];
@@ -2279,6 +2273,84 @@ firstInstanceCalendarDateRange: (NGCalendarDateRange *) fir
   return error;
 }
 
+- (NSString *) davNotifyOnPersonalModifications
+{
+  return [self davBooleanForResult: [self notifyOnPersonalModifications]];
+}
+
+- (NSException *) setDavNotifyOnPersonalModifications: (NSString *) newBoolean
+{
+  NSException *error;
+
+  if ([self isValidDAVBoolean: newBoolean])
+    {
+      [self setNotifyOnPersonalModifications:
+              [self resultForDAVBoolean: newBoolean]];
+      error = nil;
+    }
+  else
+    error = [NSException exceptionWithHTTPStatus: 400
+                                          reason: @"Bad boolean value."];
+
+  return error;
+}
+
+- (NSString *) davNotifyOnExternalModifications
+{
+  return [self davBooleanForResult: [self notifyOnExternalModifications]];
+}
+
+- (NSException *) setDavNotifyOnExternalModifications: (NSString *) newBoolean
+{
+  NSException *error;
+
+  if ([self isValidDAVBoolean: newBoolean])
+    {
+      [self setNotifyOnExternalModifications:
+              [self resultForDAVBoolean: newBoolean]];
+      error = nil;
+    }
+  else
+    error = [NSException exceptionWithHTTPStatus: 400
+                                          reason: @"Bad boolean value."];
+
+  return error;
+}
+
+- (NSString *) davNotifyUserOnPersonalModifications
+{
+  return [self davBooleanForResult: [self notifyUserOnPersonalModifications]];
+}
+
+- (NSException *) setDavNotifyUserOnPersonalModifications: (NSString *) newBoolean
+{
+  NSException *error;
+
+  if ([self isValidDAVBoolean: newBoolean])
+    {
+      [self setNotifyUserOnPersonalModifications:
+              [self resultForDAVBoolean: newBoolean]];
+      error = nil;
+    }
+  else
+    error = [NSException exceptionWithHTTPStatus: 400
+                                          reason: @"Bad boolean value."];
+
+  return error;
+}
+
+- (NSString *) davNotifiedUserOnPersonalModifications
+{
+  return [self notifiedUserOnPersonalModifications];
+}
+
+- (NSException *) setDavNotifiedUserOnPersonalModifications: (NSString *) theUser
+{
+  [self setNotifiedUserOnPersonalModifications: theUser];
+
+  return nil;
+}
+
 /* vevent UID handling */
 
 - (NSString *) resourceNameForEventUID: (NSString *) uid
diff --git a/SoObjects/SOGo/SOGoObject.h b/SoObjects/SOGo/SOGoObject.h
index dc26fd78e..172f45a60 100644
--- a/SoObjects/SOGo/SOGoObject.h
+++ b/SoObjects/SOGo/SOGoObject.h
@@ -166,6 +166,10 @@
 		     parameters: (NSArray *) params;
 
 /* utilities */
+- (NSString *) davBooleanForResult: (BOOL) result;
+- (BOOL) isValidDAVBoolean: (NSString *) davBoolean;
+- (BOOL) resultForDAVBoolean: (NSString *) davBoolean;
+
 - (NSString *) labelForKey: (NSString *) key;
 
 /* description */
diff --git a/SoObjects/SOGo/SOGoObject.m b/SoObjects/SOGo/SOGoObject.m
index 8736cf050..44cc83647 100644
--- a/SoObjects/SOGo/SOGoObject.m
+++ b/SoObjects/SOGo/SOGoObject.m
@@ -27,6 +27,7 @@
 #import <Foundation/NSClassDescription.h>
 #import <Foundation/NSFileManager.h>
 #import <Foundation/NSPathUtilities.h>
+#import <Foundation/NSSet.h>
 #import <Foundation/NSString.h>
 #import <Foundation/NSURL.h>
 #import <Foundation/NSValue.h>
@@ -1582,6 +1583,35 @@
   return exception;
 }
 
+- (NSString *) davBooleanForResult: (BOOL) result
+{
+  return (result ? @"true" : @"false");
+}
+
+- (BOOL) isValidDAVBoolean: (NSString *) davBoolean
+{
+  static NSSet *validBooleans = nil;
+
+  if (!validBooleans)
+    {
+      validBooleans = [NSSet setWithObjects: @"true", @"false", @"1", @"0",
+                             nil];
+      [validBooleans retain];
+    }
+
+  return [validBooleans containsObject: davBoolean];
+}
+
+- (BOOL) resultForDAVBoolean: (NSString *) davBoolean
+{
+  BOOL result;
+
+  result = ([davBoolean isEqualToString: @"true"]
+            || [davBoolean isEqualToString: @"1"]);
+
+  return result;
+}
+
 - (NSString *) labelForKey: (NSString *) key
 {
   return [self labelForKey: key inContext: context];