So I've been all over the place trying to figure out how to fix this. It started happening after I installed the second FroYo 2.2 that was released.
Anyways, I open Rom Manager and hit 'Download Rom'. It says I need to update to the new version of Rom manager. It takes me to the market, and the download just sits there and does nothing. I hit Cancel, and it FC's. Try it a couple more time with the same result so I just left it like that for a while (days).
Finally I decide to go into my Applications under settings and uninstall it this way. That worked, then I go back to the market to re-download. Start the download, and it gets hung up again. Download bar makes no progress. So I leave it there for a day. Come back the next day, still sitting there. Can't press 'Cancel Download' or it just FC's. Now I am totally stuck.