From Bugzilla Helper:
User-Agent: Mozilla/4.76 [en] (X11; U; Linux 2.4.5 i686)

Description of problem:
Apparently at least some 7.1 x86 kernels incorporate patch-2.4.2-ac3, which
breaks lseek on /proc/N/mem, giving a bogus EINVAL error for seeks to the
top half of a process's memory.  This breaks SUBTERFUGUE
(http://subterfugue.org) and perhaps other programs.

How reproducible:
Didn't try

Steps to Reproduce:
1. This is from a user error report

2.The systems are stock RedHat 7.1, running the 2.4.2-2 RedHat supplied
kernel.
Have tested with both smp and up versions.
Linux slave6 2.4.2-2smp #1 SMP Sun Apr 8 20:21:34 EDT 2001 i686 unknown
These are burnup systems, generic installation via kickstart.
3.  If you obtain and build SUBTERFUGUE, the command 'sf --tri=Trace date'
would trigger the bug.
	

Actual Results:  You'll see a python backtrace.

Expected Results:  successful execution

Additional info:

This bug appears to be fixed as of the 2.4.5-ac1 patch.  It's also absent
from all vanilla kernels, I believe.

So, the fix is to upgrade or rebuild your kernel.  (I'm filing this bug
primarily for your errata page.)