Dragon Age: Origins
My work around, click the trainer and start the game. Do not activate trainer wait for the game to load and after a few seconds activate trainer. It works for me
If you are positive the trainer version and game version are the same, then try reinstalling the game 1.01 patch or 1.02 patch, whichever you use. Sometimes the patch doesn't install correctly which would cause the higher version trainer not to work.
The correct link is the following "social.bioware.com/page/da-patches", the 1.02 should be 37mb and then the trainer 1.02 will work.