LR has been acting up a LOT lately - freezing, etc. I've tried to clean out old libraries, but it always freezes, so i just left it alone. when i opened it up today, it took FOREVER to open, then it asked if i wanted to test for corruptioin/backup, etc (which i do once every few days), and it said something to the effect of "library is corrupt, can not open".. and that was that....
do i need to reinstall it or what?
thanks in advance for any advice

If you've been backing up your library, you should just be able to restore it. I don't have LR on this PC, but I'll check the exact process when I get home this evening.

It looks like you just paste your latest backup library into the location where the main library is. My backups are in My Documents->My Pictures->Lightroom->Backups->[Last backup date]. The main library is at My Documents->My Pictures->Lightroom. Yours may be different if you entered an alternate location when you installed it originally, but I'm pretty sure my locations are the default.

i just got back home from my earlier post.. now it won't open. it says there is a runtime error... i tried contacting adobe tech support but i never got through cause i didn't want to be on hold until tomorrow.... any ideas???

I FIXED IT!!! and i didn't have to wait, or pay to talk to tech support.
i just deleted my backup files in my backup library (i didn't need it), reinstalled, and now it opens!:)

Awesome - glad to hear crisis was averted

make sure and run the library backup and library corruption tests when the little pop up appears (usually every 7 days or so)..... very important

And do the upgrade to LR 1.1 and I believe those problems will be thing of the past.