SharePoint 2010 some users are unable to view items in the calendar

For my client many users are complaining that they are unable to view any items in calendar web part.

While browsing to the calendar you get an Error in bottom left corner in IE. Timestamp: <Date and Time> Message: Expected ‘}’ Line: 1307 Char: 463 Code: 0 URI:http://servername/sites/Lists/Calendar/calendar.aspx

Strange thing is that If the view is changed to Allitems view, items will be displayed.

Finally after a lot of troubleshooting and going through the ULS logs we found the answer.

The user account had an Apostrophe in his Email address!!!

eg:abc’s@contoso.com.

The resolution is to remove the Apostrophe 🙂

Happy Hunting..

Update: http://support.microsoft.com/kb/2405789 resolved the issue