Just wondering if this couldn't be a combination of factor, instead of just Flash.
As I had mentioned in that other thread, I usually avoid updating Flash most of the time (unless there's a security issue), so I'm still on 11.1.102.62 (same as I mentioned in that thread). My wife's running the latest version. Both of us are running Safari (latest version) - on OS X
10.6.8 though. No issues whatsoever.
I know this doesn't really help, but, anyway...
Good luck fixing the issue.