Under 2.4.16, eth0 comes up perfectly every time (using the stock kernel-image.2.4.16-586), with a custom compiled kernel-image-2.4.17, I can't get it active.
The only thing that looks suspicious at boot time is: Linux Kernel Card Services 3.1.22 options: [pci] [cardbus] [pm] PCI: Found IRQ 5 for device 01:03.0 IRQ routing conflict for 01:03.0, have irq 9, want irq 5 IRQ routing conflict for 01:03.1, have irq 9, want irq 5 PCI: Found IRQ 5 for device 01:03.1 IRQ routing conflict for 01:03.0, have irq 9, want irq 5 IRQ routing conflict for 01:03.1, have irq 9, want irq 5 Yenta IRQ list 08b8, PCI irq9 Socket status: 30000410 Yenta IRQ list 08b8, PCI irq9 Socket status: 30000006 (under 2.4.16, it finds IRQ9). However, 'cardinfo' always finds my pcmcia card (an ancient IBM dual function modem & ethernet) and makes it look functional - but ifconfig doesn't work. '/etc/init.d/pcmcia restart' always complains about non-existent i82365 module and fails to unload pcmcia_core. Then it gives me the error: /lib/modules/2.4.17/pcmcia/i82365.o: init_module: No such device Hint: insmod errors can be caused by incorrect module parameters, including invalid IO or IRQ parameters Which seems reasonable, given that it seems to be using the wrong IRQ, but what can I do to force it to use IRQ9?

