We had this issue identified a few months ago and found out that it is fully an Adobe Flash issue. Apple and Adobe had been notified about the issue and we hope that the next Flash update will resolve it.

For now, to overcome the issue you would have to revert to 10.0 of the Flash Player since it doesn't have this issue.

You can download the prior version here:
http://fpdownload.macromedia.com/get/flashplayer/installers/archive/fp10_archive.zip

All other info can be found here:
http://kb2.adobe.com/cps/142/tn_14266.html

Hope this helps. We already saw that Adobe is testing 10.2, but it currently still crashes Safari.  We're looking forward to a fix for this very soon.