For some days now I’ve been trying to get my AVM Fritzcard PCI to work with Asterisk. To no avail. While I got the mISDN driver to compile, the included driver for the AVM card would freeze the system on every second call.
Using AVM’s own driver together with chan_capi didn’t work out either. So I went out of my way and bought a cheap ISDN card that uses an HFC chipset. Guess what – no more problems using chan_misdn. My advice to AVM: Either make your driver – that’s currently only available for the SUSE distribution and only for outdated versions of that – open source or make true on not offering any Linux drivers anymore. The latter will at least make it easier for the customer to decide to not buy the product. Currently, the price/performance ratio of the Fritzcard is unacceptable for Linux users.

Thanks for the info. At this moment I’m facing completely identical problems. I will dig up my HFC based card and give it another try.
Is it by any chance an AVM Fritzcard PCI v2.0? AKA “#*$%!! fcpciv2″? AVM are no longer providing the CAPI module for this specific card for kernels > 2.6.16 (AFAIK) Might also be >2.6.18. Doesn’t really matter. Fact is that with a recent kernel you’re supposed to be fscked. “Supposed to” means AVM have -if I got it right- withdrawn support for that card after differences with the kernel group concerning future policies and binary-only kmodules.
There is, however, a not-too-nasty hack to translate the source part of the last official AVM-package with a recent gcc and copy the binary part into /lib/modules/`uname -r`. Works perfectly for me – especially with Asterisk’s brand new version of chan_capi.
I forgot – the link for the fcpci-Hack is: http://www.linuxmaker.com/tutorials/fritzcard-module.html