When connecting an FTDI chip (some sort of RS232 over USB) over any
USB hub, the system crashes (blue screen) telling:
STOP: 0100000050 (0xE7CA9000,0x00000001,0xF7A36050,0x00000001)....
usbhub.sys Address F7A36050 base at F7A2D000 Datestamp 41107d68

I've tried several different hubs of different manufacturers but the
problem is more or less the same.

I've contacted the manucturer of the USB chip (FTDI) but they say,
that it wouldn't be their problem because usbhub.sys is from
microsoft. And using the chip directly connected to the notebook works

I have to decide whether we can sell the product with this chip or
not. Can anybody give me some hints?