asterisk users - Feb 2007 - install-misdn compile problem with debian

Hi,
I get this error while compiling install-misdn on a Debian box with 
kernel 2.6.18:

*make[2]: *** 
[/usr/src/install-misdn/mISDN/drivers/isdn/hardware/mISDN/hfc_multi.o] 
Error 1*
*make[1]: *** 
[_module_/usr/src/install-misdn/mISDN/drivers/isdn/hardware/mISDN] Error 2*
*make[1]: Leaving directory `/usr/src/linux-headers-2.6.18-2-486'*
*make: *** [MISDN_MAKE_MODS] Error 2

*anybody knows why?

TIA

Giorgio