B'E'B . . . . .
I've had this sort of snag before; even with flash installed, due some kind of corruption along the line.
Click
HERE first of all and do a test on your installation. If any problem, the page should offer you an option to update or install.
If no luck, would suggest uninstall Shockwave and Flash completely - via Add/Remove - and reinstall. Link (above) from this stage will also accommodate that (page sometimes takes a moment or two to get its act together).