version YPOPs! v0.9.5.14 stopped working recently (after 3/12/2009).
so, I updated to YPOPs! Version 0.9.7.3.
it fails in exactly the same way
on the HTTP GET command for message 1 after the UIDL proved the message exists.
see attached YPOPS! log file for proof
ypops log
failure proof