..error in hostap.o!!!

[andreaf at cs.columbia.edu]

Hi everyone,
everything was working with HostAP, but when I went to recompile, it gave
me this error (at the make_install):

depmod:   ***Unresolved symbols in /lib/modules/2.4.21-WIFI/net/hostap.o

I do not understand why I get this message now.
I am using Mandrake 9.1 and the only thing that changed since before is
that I had a system crash and the system had to recover. It did tell me
that I could loose some data.
Do you think this is the problem? What do I have to do/install to make it
work again?
Thanks all,
Andrea