...ok, here's a little update...
after farkin' around with thing damn thing most of the evening, i was able to get the adobe uninstaller program to remove the problem version, then i installed the archived version that joe provided a link for. after installing this archived version, i was able to log on to youtube, but could not view videos. also i was still unable to log into tinychat.
...so i uninstalled flash again, then rebooted and then installed the debug version. now i can log in to chat, and can view youtube videos, but most of them appear very choppy especially on full screen.
but hey, at least i can view them and can get into chat again!
(...i still liked the old chat better...

)