Asterisk under Xen 2.0

I have a Xen 2.0-testing/Linux 2.6.12/SuSE 10.0 installation which
supports a small consolidated server cluster with PCI access from DomU’s
to Hauppauge TV cards and a network card. So far so good.

I’ve been trying for some time to establish my Asterisk PBX in a DomU as
well, but keep hitting a brick wall with the drivers for the Digium
TDM400P PCI card. Drivers compile, but raise a segmentation fault on
module loading in DomU. It all works in Dom0.

Any ideas - including diagnostic strategies re Xen DomU PCI interface
would be welcome.