[SOLVED]{r,f}xfax - undefined symbol


i have a mandrake 10.1 system, asterisk, spandsp, apps_rxfax, apps_fxfax compiled right, but asterisk fails with this error:

[app_txfax.so]Apr 11 03:18:14 WARNING[12398]: loader.c:325 __load_resource: /usr/lib/asterisk/modules/app_txfax.so: undefined symbol: t30_get_far_ident
Apr 11 03:18:14 WARNING[12398]: loader.c:554 load_modules: Loading module app_txfax.so failed!

asterisk 1.2.5 with spandsp-0.0.2pre25
maybe it is a version problem somewhere, but i cant imagine where.

any ideas?

it is important to configure spandsp with --prefix=/usr option on mandrake.