Been struggling with this myself for the past couple days (new Liberty user here), but none of the suggestions in this thread were working. A random google search happened across this link today: Liberty 0.9 Market Update Fix - Pastebin.com
Downloaded the file, pulled the Vending.apk out of the zip, uninstalled the old version of the Market through ROM Toolbox, installed the new one, and I finally have a fully-functioning copy of the new market. Downloaded and installed a couple random apps to test it out. Seems to be working perfectly.
(Note: I don't know where any of this stuff came from, or if it's hidden somewhere on this forum that I haven't seen already. Just wanted to share what worked for me)
Downloaded the file, pulled the Vending.apk out of the zip, uninstalled the old version of the Market through ROM Toolbox, installed the new one, and I finally have a fully-functioning copy of the new market. Downloaded and installed a couple random apps to test it out. Seems to be working perfectly.
(Note: I don't know where any of this stuff came from, or if it's hidden somewhere on this forum that I haven't seen already. Just wanted to share what worked for me)