Have you tried clearing the data for the market thru the settings>app>manage apps. Usually works for me. As for link to an older market you should be able to get it outta any rom tar file, then just put it on your sd card and install it
The old market apk from ComRom is right in the system/app folder of the zip. And I had the same issue with the new market, but I did just what sabban said, wiped the data for the market and it found all my installed apps after that.
I notice something weird tonight. After reading this post I decided to try clearing my market data. I was having no problems but I did it anyways. I immediately found an update that wasn't there before. Hmmm. So I do the same thing on my wife's fascinate. Nothing unusual but shortly afterwards I notice that she is now on market version 3.0.28 and I am on version 3.0.27. I should note that I installed both from a manual market apk download when the new market was released.
So I fight with my phone for a while trying to get it to update to 3.0.28. No luck. Now I checked my wife's phone again and her market version has gone backwards to 3.0.27. Was I seeing things?????
I had a different sort of issue. I was getting all sorts of weirdness on CM7 and the new market app. It kept insisting that I didn't have enough storage capacity on my phone and wouldn't let me update or install new apps. I pulled that old market off of my backups and that didn't help either. I finally had to just reflash gapps and it gave me the old market again which fixed the problem.