I've uninstalled flashplayer... reinstalled it... uninstalled firefox...
reinstalled a newer version and i keep getting the same error.

"The QuickTime Plug-in requires QuickTime System extention version 5 or later"

Quicktime is gone.... comepletly, using the uninstaller.

Any ideas how i can get back to flash player handling flash in firefox again?

I've had the same problem.
Try this:
Otherwise, find the file "npqtplugin.dll" on your computer. It is likely to be
in the "plugins" folder of your Internet Explorer or Firefox installation
directory. By default, this would be "C:\Program Files\Mozilla
Firefox\plugins" . Once you have located the file, delete it (or move it to a
different folder if you might want to re-install it later).
Keep in mind that there may be multiple copies of the file. Some copies might
be named "npqtplugin2.dll" or "npqtplugin3.dll". You need to get rid of all of
them.

Also, keep in mind that, by default, the Windows File Explorer does NOT
display filenames that end in ".dll". So, to locate the files, you should use
the "Find/Files or Folders..." command in the Windows "Start" menu. (Or, you
can enable the display of all files using the "View/Options..." command of the
Windows File Explorer.)
Good luck