switching from 2.2 to 2.4 kernels

[rich <rich@octopus.debian.org>]

Hi,

Running a debian testing box on a lan behind an ipchains masquerader attached 
to a cable modem,  I tried to upgrade to 2.4.9-686. When running 2.4.9-686 
(version 2.4.9-1), I could not access my server's POP3 or SMTP server: I got 
connection refused when doing "telnet pop3.blueyonder.co.uk pop3". Rebooting 
into 2.2.19--10 fixed it. Both kernel versions are fresh installs, untweaked 
by me (I reinstalled everything following disk failure)

1. Does anyone have any ideas what differences between 2.2.19 and 2.4.9 might 
cause this? 
2. Is it a bug in the 2.4.9 versions that they break the 2.2.19 functionality 
without telling us?

cheers, Rich.