If you uninstalled a version of the Adobe flash plugin with Add/Remove there could be some traces left behind. Adobe provide an uninstaller which you run, reboot and then reinstall the plugin. Have a look here (and note the info for IE users):
http://kb.adobe.com/selfservice/view...4157&sliceId=1 (Note that this uninstaller will remove the flash plugin from all browsers installed on the system so, if you have Firefox, Opera or Netscape, you will have to reinstall their version of the plugin as well).
If you don't have it handy, here's the link for the Active X version of the plugin (I think you have to be online while it installs, check the instructions before you start);
http://www.adobe.com/shockwave/downl...x/English.html