Module help

[ky0dr at kc.rr.com]

Here's one for you module experts.  I've been using them for a while, and 
managed to blunder my way through eventually, but never felt I've really 
understood the big picture.

Here's the deal.... I've been using a "dmfe.o" driver for my on-board 
Davicom 10/100 Ethernet "NIC".  Worked well enough for most uses, but would 
occasionally cough and recover, and on rare occasion it let some garbage 
through (don't know how, but I would occasionally get a corrupted image - I 
deal with a lot of images from my digital camera - shift-reload would fix it).

Tired of the throughput penalty (frequent pauses in the data transfer) when 
moving boat-loads of pictures around my LAN, last night I upgraded to the 
latest version of the dmfe driver.  I downloaded the source and compiled it 
per the directions.  When I "rmmod" the old one and insmod, I get a message 
indicating unresolved dependencies or symbols (I forget the exact term; I'm 
away from the system at the moment).  Also, my "ifconfig -a" doesn't show 
the eth0 anymore - probably just need to re-init the interface 
somehow.  When I reboot, I get the same unresolved error message, yet the 
interface works fine, near as I can tell (and no pauses in the data transfer).

So... any hints on how to track down and solve the issue?

Any good, well-rounded module primers on the net that are recommended reading?

My system is RH 6.2 (kernel 2.2.14-something).

David