[help] Warning: Bad message number in ...

[Derry Santoso]

Hello,

I'm installing IMP 2.2.3 with php 3.0.6. Everything goes well
except one. When I click 'Message Source' to an email with
long header (eg: from mailing list), there's message in the popup windows:

Warning: Bad message number in /usr/local/apache/htdocs/horde/imp/view.php3
on line 81
Warning: Cannot add more header information - the header was already sent
(header information may be added only before any output is generated from
the script - check for text or whitespace outside PHP tags, or calls to
functions that output text) in /usr/local/apache/htdocs/horde/imp/view.php3
on line 82

But, it doesn't happen to short header emails.
What's wrong? Is there anything I should do to get rid of this message?

Thank You,
Derry Santoso