Calendar Invites showing as normal email w/attchmnt

I use a 8520 with OS5.XX. Recently i accidentally got my BB swiped and got it restored from my employer support team. Earlier whenever i got an meeting invite it used to show up differently and i could Accept, Tentative, Decline them.

But from the time i got it re-activated, calendar invites show up as regular email with attachment. But i can still see them as invites in my laptop Outlook. Also when i accept meeting, it is not getting updated in BB calendar.

Please help. I am missing lot of meeting because of this :(

try deleting the desktop CICAL calendar entry and having your IT department resend your service books. Also make sure that wireless sync is turned ON in your calendar options.