None of our powerpoint attachments to work items are opening when we
click on the filename. This used to work before beta 3 and this is
the first time we have tried it since upgrading.

I assume you are using IE6 or IE7? There is a recent issue that is most
likely what you are seeing:

https://jazz.net/jazz/resource/itemName/com.ibm.team.workitem.WorkItem/57472

And with the same cause:
https://jazz.net/jazz/resource/itemName/com.ibm.team.workitem.WorkItem/56872

These are most likely triggered by a bug in IE wrt handling of the
Cache-Control: no-cache header, e.g. http://support.microsoft.com/kb/812935.

HTH,
Patrick
Jazz Work Item Team