Optiplex 160L - PCI NIC installation problems

I have an integrated Broadcom 440x installed and it works fine.  But I want to try a PCI NIC (3COM905).  I disable the Broadcom 440x via the BIOS and install the NIC on a free PCI slot. The OS Device Manager(WinXP Pro) recognizes the device and loads necessary drivers.  I plug the CAT5 cable but the link lights don't light and I receive a message that the network cable is unplugged to the NIC.  The NIC is tested on other Optiplex 160Ls and other PC and works fine.

I try installing a generic USB NIC and same story:  OS recognizes the device installed but link lights remain off and notification of network cable unplugged.  Tried all USB ports and PCI slots with the same result.  I haven't tried any other PCI devices.   Any ideas?  Thanks.