Hi Ted,
Could be many things, we should start with this...
"Try Disk Utility
1. Insert the Mac OS X Install disc, then restart the computer while holding the C key.
2. When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu. (In Mac OS X 10.4 or later, you must select your language first.)
Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Disk Utility.
3. Click the First Aid tab.
4. Select your Mac OS X volume.
5. Click Repair. Disk Utility checks and repairs the disk."
http://docs.info.apple.com/article.html?artnum=106214
Then try a Safe Boot, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, reboot when it completes.
(Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive.)
You should first uninstall any previous version of Flash Player, using the uninstaller from here (make sure you use the correct one!):
http://kb2.adobe.com/cps/865/cpsid_86551.html#prob1=uninst,os=m10.6,
Download this if you haven't...
http://fpdownload.macromedia.com/get/flashplayer/installers/archive/fp10.1.102.6 4_and_9.0.289.0archive.zip
Once downloaded if it doesn't unzip automatically the double click on that file.
Look for the fp10.1.102.64_and_9.0.289.0archive folder, open it, look for the Flash Player 10.1.102.64 folder & open and look for 101r10264 folder & open it, double click on the flashplayer101r102_64_ubmac.dmg file, choose the Install Adobe Flash Player file to install... they don't make it easy!
Or smaller here...
http://dl.dropbox.com/u/450421/flashplayer10_1r82_76_ub_mac%20copy.dmg.zip
Stand alone player...
http://dl.dropbox.com/u/450421/LastFlashPPC.zip
Or free 3rd party...
http://www.wimpyplayer.com/products/wimpy_standalone_flv_player.html