Problem in installing spandsp

I have installed tiff-3.72 and spandsp-0.0.2pre26 in asterisk1.2.7 and reinstall asterisk1.2.7. But when I can not start asterisk.Below is the alarm:

[app_rxfax.so]Dec 13 11:46:55 WARNING[24056]: loader.c:325 __load_resource: /usr/lib/asterisk/modules/app_rxfax.so: undefined symbol: t30_get_far_ident
Dec 13 11:46:55 WARNING[24056]: loader.c:554 load_modules: Loading module app_rxfax.so failed!
Ouch … error while writing audio data: : Broken pipe

why not just upgrade to a newer version of Asterisk? that version of spandsp 0.26 was released May of 2006.