Thank you for posting all the details. It helps, especially since the first solution I was about to suggest was one you already tried (fresh reinstall).
_____Try this Adobe Flash crashing fix_____
Using Firefox, disable “hardware acceleration”.
Step 1 – Open Firefox and go to this Adobe link: http://helpx.adobe.com/flash-player/kb/find-version-flash-player.html#main_Find_Flash_Player_version_type_and_capabilities__Flash_developers_only_
Step 2: Scroll down to #5 on the list. There should be a square animation there. RIGHT-click the animation and select “Settings…”
Step 3 – UNcheck the “Enable hardware acceleration” box.
Step 4 – Close/Exit Firefox. Then open it up again. Perform Step 1 and 2 again above. Verify that the Enable hardware acceleration checkbox is NOT checked.
Step 5 – Using Firefox, play a Zynga game that uses Flash and usually crashes on you.