Any chance you are exporting to a folder where you don't have write permission?
No, simply to the desktop. I have tried exporting to other folders as well (with no luck).
Perhaps try closing your copy of Excel first.
Is this a scripted process or manual. If scripted, try a manual. If manual, try a Save as Excel and see what rsults you get.
Tried it each way, manual, scripted, save/send records as...
It's looking like a deactivation and reinstall might be in order.
The deactivation and reinstallation of FileMaker Pro 9 may not fix the problem. If you are on a Macintosh, you may have a corrupt preference file. Try removing the preferences file before the deactivation and reinstallation:
Home -> Library -> Preferences -> com.filemaker.pro.plist
Once removed, go back into FileMaker Pro and try exporting again to Excel again.