TrackIR is designed to run in the background and works well in FS9 and other games with TIR support.
I'm surprised that no one in these forums has thrown something usefull at me yet! Is there anyone else here with FSX and TIR4?
I did throw something useful at you, but you never said whether or not you ran it on high priority, becuase if you do, FSX will always use any resources it needs, whether or not TrackIR is using them. Even though TrackIR is designed to run in the background, it requires memory, and CPU resources to run, and if FSX is using most or all of these resources, TrackIR will not run.
If that doesn't work, open up TrackIR and check to make sure that your profiles are set up correctly for FSX. See if you have FSX set to the profile that you normally use, otherwise your normal hotkeys may be different and might not work.
Otherwise, you'll have to tell us more about your problem. Is your TrackIR plugged in? Is there a light source or reflective material behind you that would wash out the dot reflection? Do you still have a dot, or did it accidentally fall off? You'll have to tell us more specifics, because I can get my TrackIR to work just fine.
If you're unhappy with the help here, try
http://www.naturalpoint.com/trackir/ , becuase they are the TrackIR site, and we are an FS site.
I hope that was useful, because apparently my advice before was just useless c**p.
