[imp] Empty Logout Screen with PhP 5.0.2

[Josh Trutwin]

I just tried upgrading my version of PhP from 4.3.8 to 5.0.2 on a development box.  I was quite pleased to see most of the Horde/IMP functionality working just fine.  One odd thing though, when the user presses Logout, they are sent to login.php?reason=logout but the screen is blank.  If I press refresh on the browser then it goes back to the login screen.  My conf.php has logout_redirect set to false.  This worked fine with PhP 4.3.8.  Not sure if it's a PhP bug or something else in Horde/IMP?  I'm not seeing any errors in the php or apache error logs.  

Apache 2.0.51
PhP 5.0.2 (built from source)
Horde 2.2.6 (same results with 2.2.5)
Imp 3.2.6
Linux Slackware 10

Any additional information I can provide?

Thx,

Josh