Richard Dawe [off-list ref] :
[...]

IRQ routing seems to be disabled in 2.6.10. I got a warning about an 
unhandled interrupt for the VIA 8255 (I think that's the right number) 
on shutdown. I'm wondering if there is some bad interaction between the 
VIA chipset and the 8110 chipset.

Possible. I hope the networking does not perform better when you are
listening to music.

Another datapoint: On a Netgear switch at work, I had to put the chipset 
into 100Mbps half-duplex and set the MTU to 576 bytes, to get any decent 
performance out of at it.

Anyway, I need to do more investigation.

Could you send an updated dmesg, lspci -vvx, /proc/interrupts please ?

Did you remove the other OS from the laptop ? I'd be curious to know
if it can teach us something.

--
Ueimor