[imp] Can't login on upgrade from IMP 4.1.6 to 4.2-RC3

[David Purdy]

Hi,

I'm running a ubuntu box with postfix IMAP and all that jazz.  I was 
able to do a clean install of Horde 3.1.7 and IMP 4.1.6 and everything 
works fine with imp authentication.

I upgraded Horde to 3.2-RC3 and everything was good

When I upgraded IMP 4.2-RC3, i can no longer log in to the suite, and 
all I get is a login failed message.  I have attempted to pour over the 
existing list archives as well as google searches and wiki pages to no 
avail.  What could have changed between the upgrade that could have 
caused this?  Any help would be greatly appreciated.