Though bugs may of course show up in a particular version of CW Recovery, from my experience w/these problems w/recovery not launching, I really think this is an issue w/ROM Manager downloading/flashing CW Recovery...something in that process isn't working reliably on Froyo. Otherwise flashing to an older recovery and then back to the same one wouldn't be able to fix things. In the end it seems like the fix needs to come from ROM Manager, not from a particular version of CW Recovery.