[imp] imp login / logout errors

[Joe Cave]

hello,
i've just installed horde/imp for the first time and i'm getting a couple errors on login and logout. the errors are as follows:

login:
======
Warning: Undefined variable: getvars in <web directory>/horde/lib/Maintenance.php on line 159

Warning: Cannot add header information - headers already sent by (output started at <web directory>/horde/lib/Maintenance.php:159) in <web directory>/horde/lib/Maintenance.php on line 159


logout:
=======
Warning: Constant sid already defined in <web directory>/horde/lib/Prefs.php on line 91

Warning: Cannot send session cache limiter - headers already sent (output started at <web directory>/horde/lib/Prefs.php:91) in <web directory>/horde/lib/Prefs.php on line 91


the weird thing is that after i get the login error if i hit back in the browser i get my inbox. any help/insight with this is much appreciated. my system info is below:

redhat 7.2
kernel 2.4.18
php 4.1.2
horde 2.0
imp 3.1
courier-imap 1.4.5
mysql 3.23.49

- j