APIC usb MPS 1.4 and the 2.4.2 kernel

[David DeGeorge]

I am running 2.4.2 as obtained from redhat, but I have experienced the same 
problems with a kernel compiled from the 2.4.2 sources at kernel.org.
I am experiencing troubles with enabling MPS 1.4 and USB. I have an ABIT VP6 
motherboard with two stock 733MHz PIIIs.
If I set MPS1.1 in the bios then my IOmega Photoshow usb zip drive works, the 
usb interrupt appears on irq 9 and after a day or two I experience  a hard 
(sysreq doesn't work) lock. It seems usb related since doing usb things i.e. 
mounting the drive sometimes cause the lock.
If I set MPS1.4 in the bios  then the usb interrupt appears on irq 19, whose 
count is alway zero, and the zip drive doesn't get registered. If give the 
noapic command line then things appear to work, irq=9,don't know about the 
hard locks, but booting seems much slower. Of course I can provide much more 
information but I wonder is this a common problem and what are the 
consequences of the noapic command?
David