dial-up bsod

ok, doing some work for a client who still uses dial-up

specs:
Acer Notebook model Aspire 3620
Intel celeron 1.6ghz mobile type processor
enough ram
windows xp home running sp3

this model is for price savvy customers, so most components are onboard incl ac97 sound, ethernet, and a mislabeled ac97 modem.

problem:
attempting to dial a connection calls BSOD giving error DRIVER_IRQL_NOT_LESS_OR_EQUAL
no file associated with the error, just that plus the stop code...

my initial thought was its obv driver conflict associated with the modem, so i uninstalled the driver / reboot / reinstall the modem driver from acer's website. (foxconn, although device manager calls it ac97) upon swapping the driver files to the HDD, it also BSOD the same way.

no luck finding a fix, all drivers for the modem i've tried cause BSOD.

NOTE: 1/5 reboots something will magically happen, and the modem will properly dial out for a connection. the other 4/5 times its definate BSOD.

irq conflicts are the bane of my existance and i'm out of my league. HELP!