Restoring Frame from Event Log Just Cleared my Entire Workspace

Hi all,

I ran into a frustrating issue on Friday afternoon where I restored a previous frame from my event log & then my entire workspace was gone/cleared. A run-down of the process:

-working on a specific part before lunch; saved part to workspace (did not upload), restarted computer while I made lunch

-approximately 30 minutes later, loaded saved part to session & noticed that none of the changes I previously made were there; checked event log to make sure save went through & found frame that confirmed save action happened

-clicked on "apply this event", waited, & was then asked to clear my session; hit yes, & then suddenly everything in my workspace was gone (all local/uploaded/modified changes lost)

Why in the world would this happen? I probably lost ~2 weeks of work because of this.

Thanks.

EDIT: Creo version 5.0.4 & Windchill version 11.0