Very odd, your problem...
If you have downloaded MainMenu (google with this spelling, if you don't have it), run all the
Cleaning scripts, more importantly the
User Cache and the
System Cache - Deep Clean scripts, restart, then try again what I suggested earlier.
If that doesn't work...
There is an article from
MacOSXHints.com where I found this comment (you'll have to use Terminal for this):
You can also do this from the command line with the mdutil command. Launch Terminal and enter:
sudo mdutil -E /
and the index file will be erased and rebuilt. The "/" stands for the boot volume; you can substitute the pathname of any volume here.
Substitute "-s" for "-E" to show if indexing is enabled on the volume, and "-i on" or "-i off" to enable or disable indexing. Note that mdutil must be run as root; hence the sudo.
You can also use mdimport to index a subset of files:
mdimport ~/Documents
would index your Documents folder and
mdimport -r /Library/Spotlight/AppleWorks.mdimporter
would index all AppleWorks files on your computer.
mdimport -L
will list all installed metadata importers.
If that doesn't work, there are other suggestions, maybe you could sort through them and use other ideas from the comments.
I really can't help with Terminal though so if you need further explanations, someone else will have to take it from here.
Keep us up to date. Good luck!