Any Letterman fans out there? Well, here's one to try if you have the FSX demo:
 
Launch any flight and turn on Mouse-as-Yoke (from the right-click menu or by pressing CTRL+Y). Fly around for a bit and then press the middle mouse button (or mouse wheel button as the case may be). Notice anything funny?
 
Somehow we mapped the SLEW_RESET command to the middle button in normal mode--a bit of a pain if your hand happens to slip. Fixing this means going to the control assignments dialog and removing the mapping. Unfortunately we make this difficult because we filter the assignments based on mode so you won't see this in the list. Hooray us!
 
Anyway, to remove the mapping try assigning any other command to the middle button. You should see a message in the assignment dialog to the effect of, "Button 2 is already mapped to blah, blah, blah." Click OK and you should now see Button 2 in the assignment list. You can now click Delete Assignment then OK and clear the assignment. Phew! Keep this tip handy because we may not fix this in the final release (to keep from breaking something else). Instead we'll add it to the FSX blooper reel. <g>