I used to see these in 1.5.x, and now their back.  Did the fixes 
that got into 1.6.x not make it into the 2.0 tree?  

Basically:

fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
fxp1: WARNING: SCB timed out!
...

fxp0 at pci0 dev 4 function 0: i82559 Ethernet, rev 8
fxp0: interrupting at dec 6600 irq 20
fxp0: Ethernet address 00:02:56:00:0f:ad
inphy0 at fxp0 phy 1: i82555 10/100 media interface, rev. 4
fxp1 at pci1 dev 3 function 0: i82559 Ethernet, rev 8
fxp1: interrupting at dec 6600 irq 32
fxp1: Ethernet address 00:02:56:00:0f:ae
inphy1 at fxp1 phy 1: i82555 10/100 media interface, rev. 4

NetBSD vinland 2.0E NetBSD 2.0E (GENERIC) #0: Tue May 18 01:20:47 CEST 2004  tron@lyssa.zhadum.de:/export/scratch/tron/build.19008a/obj/sys/arch/alpha/compile/GENERIC alpha

I'm running with a single CPU at the moment, I did try GENERIC.MP initially
on two CS20s, but they'd lock up within a day and I couldn't break to a 
debugger or if I could I'd have to power cycle to get the machine back up.