Logon field & sessions help please

I have problems with logon field of imp/horde. It always has '<USE_SESSION_ID>' in the field when the page is loaded for the user to logon. The user always has to remove this to enter their username. How can I stop this from appearing at the logon screen for the users. I have the default php.ini (ie nothing in there). The logon of imp uses sessions. Im using Mac OS X 10.3, PHP 4.3.3, Horde 2.2.4 and IMP 3.2. I have no idea why this is happening? Can someone point me in the right direction. Thanks, Ian ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.