Do you have either Quark2ID or Extensis Suitcase Fusion installed?
Both are known to cause this problem.
To find out, instead of Force Quit, go to Activity Monitor, select InDesign, and View > Send Signal: Abort (SIGABRT).
You will get a crash report.
Upload it to http://pastebin.com/ and post a link here.
I have Suitcase Fusion installed. I'll try the crash report upload next time it happens (doesn't happen every time) and post a message. Any solutions if Suitcase is the cause?
Solutions? Not really...I think there might be an older version of Suitcase that doens't have this problem...talk to Extensis?