It does seem odd. When you used a static address did everything work ok? Is there a reason you don't want to use a static address?

Nope, its never worked in Slack, even setting it up with the static IP address, gateway and DNS servers in /etc/resolve.conf

What network card are you using (make & model)?
You say that windows works fine - is this on the same PC?
Are you using the same cable as you used when it works with windows (this is a bit of a long shot)?

Yes, as you can see from my post, it works fine in J.A.M.D. Linux and Windows with exactly the same equipment (network card, modem, cable) and it works fine between reboots with either system, except of course Slackware. I've now taken J.A.M.D. and have one drive with Win98 on and Slackware on the other.

What driver are you using in J.A.M.D?

Tulip, same as slackware

The only thing I can suggest is recompiling it. your configuration seems ok but the software doesn't seem to be able to communicate with the hardware.

The tulip module? I've tried reinstalling a few times, and I tried with Slack 8.1, 9.0 and 9.1.

Yes - I'm affraid that is the only thing I can think left to try is recompiling it on your own machine.

Well I would of got this one worked out a little quicker if my monitor hadn't of blown up the other weekend :-( Thanks to David I looked into my network card. I've used it on a hub in a basic network setup, with the tulip kernel module being auto-detected in Slackware. As it just worked, I'd never looked into it further, it was on £2.75 but its always done its job. I took it out and discovered it was a Davicom DM9102AF. This uses the dmfe kernel module, however this is disabled in /etc/hotplug/blacklist. If you remove the hash from said blacklist, the dmfe module won't load on boot. The tulip module is loaded, so if you then remove that with rmmod and then load dmfe with modprobe, the dmfe module works fine. From that very second DHCP flew up and I was connectly instantly. I should of checked the network card a lot sooner, then I could of saved myself a lot of hair pulling! ARGH!

Good bit of troubleshooting there - well done and thanks for posting your solution - I'm sure someone will find it useful in the future.