Broadcom BCM5751 not attaching on IBM ThinkCentre A51

I have a new (several, actually) IBM ThinkCentre A51 (8131-16U and 8138-14U) 
machine on which I'd like to run FreeBSD 6.0.  The machine has a "Barbados" 
motherboard with an integrated Broadcom BCM5751 gigabit NIC.  Visually, the 
Broadcom chip identifies itself as a BCM5751KFB.

The bge driver recognizes the chip and tries to attach, but fails:

bge0: <Broadcom BCM5751 Gigabit Ethernet, ASIC rev. 0x4101> mem 
0xd0000000-0xd000ffff irq 5 at device 0.0 on pci2
bge0: RX CPU self-diagnostics failed!
bge0: chip initialization failed
device_attach: bge0 attach returned 6

I saw a couple other reports and PR's with similar messages, but they all 
seemed to be related to BCM5705 chips on amd64.  I did try the two possible 
workarounds I found, but neither produced any change (running a kernel 
without APIC and increasing the delay times in if_bge.c).  Skipping 
(commenting out) the RX diagnostics check altogether resulted in a kernel 
panic (not too surprisingly).  I do not suspect faulty hardware, as the 
behavior is the same on several different machines (and the chip works fine 
with Broadcom's drivers for DOS or Windows XP).

What's the next step toward getting this chip working properly under 
FreeBSD?  Has this particular chip been successfully tested with the bge 
driver previously?

For now I will use a PCI NIC and/or the ndis driver, but I would love to see 
native support if possible.  I'm more than happy to test patches if a 
driver developer would care to work with me.  Are there any other details I 
should include in this thread or a PR?

Any input will be greatly appreciated.  Thanks!

JN