No message body?

[Jon Starling]

Horde: 2.1-cvs
IMP: 3.1-cvs
Turba: 1.1-cvs

PHP Version: 4.0.6

Having killed my install of horde recently I have reinstalled from CVS and am
having a problem...

When clicking on any message I am presented with the usual message header i.e.
who the message is from subject etc...  But the message body is missing???  If
I click "Show message source" I can see the message body is there IMP is just
not displaying it?

Have a made a mistake in my config somewhere or is PHP 4.1.0 required as the
imp/test.php implies?

-Jon