USB device support in FC3T1 (USB modem)

[John Reiser]

I'd like to get my USB modem working in FC3T1, so I can continue to use
it as a Winmodem replacement on laptops, and for credit-card processing.
It works in RH9, RHEL3 WS, FC1, SuSE Linux 9.1 Personal (kernel-2.6.5-
7.95-default); and can be made to work in FC2 via manual modprobe cdc_acm;
but I cannot make it work in FC3T1.

Some related bugzilla entries:
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=129872
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=126049
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=102368

After allowing access with filesystem permissions and loading kernel
module cdc_acm, the current stumbling block seems to be
    open("/dev/input/ttyACM0", O_RDONLY|O_LARGEFILE) = -1 EINVAL (Invalid argument)

I'm ready to help (including re-compiling kernels, etc.), but I lack
reasonable knowledge about how to attack this problem efficiently.
Would somebody please provide a clue or two?  Thank you.

-- 
John Reiser, jreiser at BitWagon.com