chan_phone configure problem


I want to use chan_phone for my Quicknet PhoneJack PCI cards. I use ixj driver from lastest kernel 2.6.22 but the problem is, that configure script in asterisk 1.4.6 is not detecting ixjuser.h :

I have a proper header file in /usr/include/linux from 2.6.22 kernel so everything should be ok - phonejack are also identified by driver in /proc/ixj and phoneX devices are created.

I also checked asterisk 1.4 from svn (revision 74511) and I had the same problem. I don’t have any idea why configure fails to identify ixjuser.h.
Thanks in advance for help.