Interesting.  Admittedly, I haven't put much extra thought or effort into the migration since I realized that it's going to be of limited value until I can support 0.6.0 (compressed public keys).  So I've kind of been neglecting it...

Are you in Windows or Linux?  If you are in Linux, you can help identify the problem by running it from the command line and observing the error output. 


If not, then I guess I'll have to bump getting a "proper logging system" implemented up on the list of priorities.  I'm not sure how to figure it out without...   I recognize it's not the best option, but if you can always create new addresses and send coins to it.  It's is a universal way to migrate funds between Bitcoin clients

The new wallet format is on hold while the main devs sort out the new wallet details, and I have a couple high priority things to do before then, anyway.  It might be a month before I can get to it...