This is a huge problem for which nobody on the net has clue about - I have thoroughly searched for answers. I have had this problem for quite a while. There are a few options:

1. If the code is corrupt the code cleaner will work - not in your case though.
2. Rebooting PC sometimes work, but problem comes back.
3. Corruption is probbably in your user profile. I have tested this and it works. When you create a new Windows user profile the problem should dissapear. You can then copy your old profile settings over. This problem is seen in Word as well, I think even Acces.

Your code has nothing to do with your problem. Even if you just create a simple endless loop in a new sub, the problem will occur:

I hope this info will help you.

Do
Loop