If they don't fix it talk to management. The computer is screwed, you are screwing your employer by not getting this fixed (I assume your computer is a vital part of your job). Sitting for 30 minutes is bullshit for you and the person that writes your checks. If you didn't install any extra crap this isn't your problem. If you did, un-install and roll the dice.
Edit: damn... scroll down a bit and I find this:
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=242x7336I think yahoo has some problems they need to fix.