I run Debian Sarge on our firm's Postfix mail server as it handles package dependencies well. Trying to improve performance I foolishly upgraded the kernel-image which upgraded approx 100 programs. After re-installing PHP5, webmail & other programs all worked well except Mailman - not moving messages at all.
To upgrade it back into operation I changed the apt source to testing and installed Mailman 2.1.9. The email lists are now working again but ALL the mailman web pages just show an "there is a bug error".

My stupidity I know, but I'm having no joy troubleshooting the error as there is nothing relevant in the Mailman logs.

I do have backups of the entire box using Bacula but I have no idea how to go back.
Any tips on how to get Mailman web pages working again or if there is an easy way back to the previous version of the OS?

Thanks,

Greg.