Yes--2 gigs will take quite a while, depending on your CPU. Once done though, the results are stored in the fileurns.cache in the preferences, and only newly added files need to be hashed.
I wonder, now, if your fileurns.cache is corrupted. If you search for it and throw it away, it will be rebuilt. You can watch the time it takes by looking at the files in the Library. Red files are unhashed, black ones are completed. Don't hit the Refresh button, or it will start all over.

Repair permissions using Disk Utility on the hard drive while running your updated system (off the CD will reset all permissions to the original settings--not a good idea).

For safe boot, just restart and hold down the shift key right after the startup chime . . . see http://www.gnutellaforums.com/showth...boot#post79186

This is the same as booting into single user mode (command-s on startup) and typing fsck -y when prompted, without having to worry about typing any damaging terminal commands. The only advantage here is that fsck -y will show you if changes were made.