I wouldn't bother updating if I were you, I did it with mine and it's just screwed the phone up, it crashes on a regular basis, it freezes up, it seems to be more bug ridden than 1.5 (if that is possible)
I have no idea if it will help or not, but if you can't get anything else to work, you might as well try. So if you are game, head on over to MoDaCo and follow the instructions in this link for "downgrading" your device: The Ultimate Pulse Owners Guide - Android @ MoDaCo
Once you've done that, you might be able to install either an older 1.5 ROM or a new 2.1. There are a number of good "guides" for doing pretty much anything you might want to do in that thread.
Incidentally, the stock ROM's are really not as good as the modified ones, particularly, I like the FLB modified 2.1 ROM. YMMV
Mine too.... Its been back for "repair and upgrade" , but they said there is nothing wrong with it and "updated" my firmware to Dec 09 Android 1.5 !!!! Now I note on the T-mobile website, they've removed the Android 2.1 update as well!!!