This system has integrated Compaq PCI Ethernet, which ran fine on IRQ 11. When I installed the D-LINK DFE-538TX/R it was not recognized. Messages appear at system startup such as: "PCI: 00:04 [0e11/4000/000600] has unknown header type ff, ignoring."
I set the IRQs to 10 and 9 for the onboard and DFE0538TX cards respectively. This step might not be required, as the first card was working fine even while sharing IRQ 11 with the video.
DFE-538TX was still not recognized even when I used Linuxconf to specify driver rtl8139 and IRQ 9. It turns out that in rtl8139.c -- at least the one provided by D-Link -- the identifications are mis-spelled for both DFE-530 and DFE-538TX.
In both cases the literals read "Adpater" instead of "Adapter". This explained why the card was never recognized. I updated rtl8139.c to fix the spellings, recompiled it and installed /lib/modules/2.2.12-20/net/rtl8139.o. The card now seems to be working fine.
One other thing is that this is a bus-mastering card, so I set this option on in the PC BIOS setup. I'm not sure if you really need this."
Last updated 2005-07-26 to correct formatting.