hsf driver not active

Hello,
i'm using mandrake 10.1 official download edition with kernel 2.6.8.1-12smp
my modem is an olitec with hsf connexant chipset, and was working before 
compiling the kernel.
the only disagriment was that i had to run hsfconfig as root to enable 
/dev/modem each time i reboot the computer.
after i compiled my kernel, i tried the rpm version for my kernel, then the 
"last chance" tar.gz version of driver,  the hsfconfig gave the following 
error :
[root@localhost sc]# hsfconfig
Conexant HSF softmodem driver, version 7.18.00.02full

If you need license keys, assistance or more information, please go to:
        http://www.linuxant.com/

When reporting a problem for the first time, please send
us the file generated by "hsfconfig --dumpdiag".

Warning: existing driver modules found under:
        /lib/modules/2.6.8.1-12mdksmp/
Would you like to keep using them? [no]

No pre-built modules for: Mandrake-10.1 linux-2.6.8.1-12mdksmp i686

Trying to automatically build the driver modules...
(this requires a C compiler and proper kernel sources to be installed)

Where is the linux source build directory that matches your running kernel?
[/lib/modules/2.6.8.1-12mdksmp/build] /usr/src/linux-2.6.8.1-12mdk

Building modules for kernel 2.6.8.1-12mdksmp, using source directory
/usr/src/linux-2.6.8.1-12mdk. Please wait...
done.

ERROR: hsf driver not active
[root@localhost sc]#
what should be done?
thank you