I have two 3com nics on my server: a 10 Mb 3c905 and a 100Mb 3c905TX, both PCI ; with the drivers shipped with 6.2 kernel the 10 Mb one is not detected correctly ( it doesn't appear in the ifconfig list, but reappers typing 'ifconfig eth1' end 'route'). Compiling the 3com source code for the same module ( found in 3com site ) and installing it fix the problem.
This sounds like it was a config error, since it showed when later ifconfig