ACPI error message; ACPI appears to be disabled by error.

I've had ACPI "work" before in the sense that the system booted properly
(though I don't know that everything was correct as I've seemed to have infrequent system hangs -- not sure if related to ACPI or not, but I don't seem to get them when it is disabled. Odd thing is that with it enabled,
system may run for a day or few. With a more recent kernel, ACPI is yielding
an error on boot which seems to "disable" any further ACPI processing.
The error (and few lines above & below)

CI->APIC IRQ transform: 0000:02:06.0[A] -> IRQ 18
PCI->APIC IRQ transform: 0000:02:09.0[A] -> IRQ 17
PCI->APIC IRQ transform: 0000:02:0a.0[A] -> IRQ 18
PCI: Cannot allocate resource region 4 of device 0000:00:07.1
ACPI Exception (utmutex-0263): AE_BAD_PARAMETER, Thread EFFC2000 could not acquire Mutex [3] [20070126]
pnp: 00:00: ioport range 0x800-0x83f has been reserved
pnp: 00:00: ioport range 0x850-0x85f has been reserved
pnp: 00:00: iomem range 0x0-0x9ffff could not be reserved

I was wondering if the error indicates a "problem" in the system's ACPI 'bios'(?). After ACPI fails, the system goes on to boot seemingly 'normally'...

Thanks,
Linda