I just purchased a "real" usb modem... that is one with a controller. Not a Win/dumb modem. It is the USRobotics USR5637.
It works on our macBook osX as well as my EeePC 1000 running Fedora 10 with my custom 188.8.131.52 kernel.
It got recognized by my EeePC right off, however, when I went to dial out with Gnome-ppp/wvdial the kernel threw an error!.
Not too good,
I tried it on the 2.6.29 rc8 as well as the 184.108.40.206 versions. Both No Go.
I googled for the error:
sleeping function called from invalid context at kernel/mutex.c:88