According to the kernel developers this is indeed the
kernel's fault.
On Wed, 2005-03-30 at 14:57 -0800, David Brownell wrote:
"Well, I'd not yet expect USB audio to work over EHCI quite
yet, though one of the patches Greg just posted should help
some of the issues with full speed iso through USB 2.0
hubs. (At least for OUT transfers as to speakers.)"
Please try this patch against 2.6.12-rc1:
http://cache.gmane.org//gmane/linux/usb/devel/33380-001.bin
Thanks, Lee, for your investigation. I'll try 2.6.12 with the
patch mentioned, but it will last some days (due to the fact
that I'm not too familiar with building kernels, even I know
how to do it :) .
Thanks & best regards
ce