Comment 1 for bug 220136

I can confirm this bug. After some inquiry, I found that the package containing chan_capi is not up to date in respect of the supplied asterisk version. It is possible to fix the problem by rebuilding asterisk-chan-capi (See http://groups.google.com/group/linux.debian.bugs.dist/browse_thread/thread/7ad0e44a2df613ff/05d2725ad1b48657?#05d2725ad1b48657 for details)

To rebuild the package:

tuxpoldo /usr/src # apt-get update
...
tuxpoldo /usr/src # apt-get build-dep asterisk-chan-capi
...
tuxpoldo /usr/src # apt-get source --build asterisk-chan-capi
...
tuxpoldo /usr/src # dpkg -i asterisk-chan-capi_1.0.2-1_amd64.deb

Since apt-get upgrade would overwrite your newly built and installed chan_capi, you have to place the debian package on hold until the bug will be fixed. You can achieve this with:

tuxpoldo /usr/src # wajig hold asterisk-chan-capi