Maybe a PCI interrupt issue? 

Forum: 3Com PCMCIA Ethernet Adapter Issues
Re: Problems with 3com 3CCFE575CT-D (John Gross)
Re: Same problem but with an error msg (Marcus Fawcett)
Date: 1999, Dec 12
From: David Hinds <dhinds@pcmcia.sourceforge.org>

Can you show a more complete message log? You can try setting PCIC_OPTS="pci_int=1" to use PCI interrupts for the card. This may require that you build the PCMCIA subsystem with PnP BIOS support enabled. -- Dave