I have just re-installed FSX/Acceleration Pack about two weeks ago. I re-installed some scenery improvements as well. All has been fine until today, when trackIr suddenly stopped working. The only other change has been that I installed the latest beta drivers for my GTX460 (301.24) Has anyone here had to deal with this happening, and is there a fix?
I tried searching the forums here, but all I found were threads about MS Flight.

TrackIR uses FSX's simconnect feature to talk to FSX, you should check if simconnect is working with other things (Plan-G or weather program like AS2012 or REX), if simconnect is still working with those other things, then most likely I would try a TrackIR reinstall.

If simconnect is not working then there's ways to reinstall it but it is pretty complicated, I had to do it a couple of years back and was able to follow some AVSIM post on how to do it.

I ran a repair install of both FSX and the Acceleration pack, but it hasn't helped. Guess I will try re-installing TIr next.

Re-installed TrackIr. Still no joy. What's next, a full re-install of the game?

You might want to do a look-see on the Naturalpoint forums in case there was some other fix, but otherwise I think that might be it...

Just one more thing, you don't have EZDok right?

I once ran into a problem where TrackIR quit working in FSX after EZDok re-install because I didn't do the reinstall from the EZDok Flight1 wrapper and so it was not fully unlocked. If you don't have EZDok (wonderful product) then ignore.

Don't have it, but thanks for the suggestion. I did have a look at the naturalpoint forums, and it looks like a common enough problem, no clear remedy however.

Might be the same bug AMD created when they released their 12.3 drivers.

When I updated to the latest version of CCC my TrackIR V5 software stopped vorking.
However, the V4 was still working.
When I asked Naturalpoint, they advised that they had found the problem an that it would be fixed in the next version.
There was a quickfix mentioned, but I rather did a fallbac, as the AMD drivers corrupted alot of other things too.

If you have not changed anything else but the graphics drivers, then it's probably that.

You may be right about that, they are a beta driver set after all. I want to keep them if I can since they are the first set of nvidea drivers that enable FXAA, which works in Cliffs of Dover.
Only FSX seems to be affected, TrackIr works fine with Cliffs of Dover, Il2, and Rise of Flight.
Edit; Just tried another un-install/re-install and it now seems to be working. Go figure.