Description of problem:
Evolution is being used as a Zimbra client.  If the user is sent more than one meeting invitation in quick succession, accepting them can lead to severe system performance problems. 


Version-Release number of selected component (if applicable):
Evolution 2.32.1-1.fc14 (64 bit)

How reproducible:
Every time.

Steps to Reproduce:
1. Evolution is being used as a Zimbra email client.
2. A colleague sends two invitations in quick succession, one to book a meeting and the second to update the time of that meeting.
3. Click on the first invitation to open it and hit the "accept" button.  (It is normally a little sluggish at this stage but bearable.)
4. Move down to second email and hit the "update" button.
  
Actual results:
Severe performance detriment on entire system.  Evolution becomes extremely unresponsive for several minutes and other applications are affected.

Expected results:
Much better responsiveness.

Additional info:
This is probably related to the issue with Evolution Calendar performance I logged as https://bugzilla.redhat.com/show_bug.cgi?id=659115