Serious em problems under -current on two different platforms [SOLVED]

[John Polstra]

Well, this is embarrassing.  It turns out there were two different
problems, neither one caused by the driver.

1. I had some ARP poisoning going on on my LAN, and that's why the two
em interfaces in the Dell box appeared to be behaving so strangely.  I
fixed that, and the box is working just fine now with the driver from
-current (both with and without MSI).  The evidence was right there
before my eyes, but it sure took me a long time to recognize it.

2. On the Tyan 2721 box, it was MSI that was causing the problem.  It
appears that MSI simply doesn't work on that motherboard.  Once I
disabled it, the driver started working fine.  I had tried disabling
MSI on the Dell much earlier, but I guess I never tried it on the
Tyan.  Maybe if I'm lucky, I'll find a BIOS upgrade that will fix it.

I apologize for wasting everybody's time as well as for taking a
year or so off Jack's life through adrenaline poisoning.

John