kernel 2.4 and Adaptec AIC-7860 panics?

[Antti.Roppola at brs.gov.au]

OK, anyone know off-hand what's happening here?

I have some HP Kayaks with onboard Adaptec AIC-7860 SCSI
controllers.

Debian default is 2.2.15 and has AIC7XXX (I presume) and
everything is good.

Another box has been compiled with 2.2.20 with AIC7XXX and
everything is good. (though I note it has SYM53C8XX compiled in as well)

I decide I want a 2.4 kernel so I can use ext3 like I am already
doing on another HP Kayak with a PCI SCSI card (AIC7XXX).

2.4.18 panics when booting the SCSI subsystem. Build with
AIC7XXX as a module and it only spits the dummy when it
tries retrieving the corkscrew from inside the bottle.

Grab a 2.4.16 kernel with AIC7XXX from the HP Kayak with
a PCI SCSI card. Nope.

Suggestions?

TIA,

Antti