Hi !
What exactly did you tryed ? It never happend to me to fail compiling the kernel... how did you tryed to compile it ?
I usualy compile it like this:

1. cd /usr/src/sys/i386/conf/
2. cp GENERIC newKernel
3. vi newKernel (and edit to fit my options)
4. config newKernel
5. cd ../compile/newKernel/
6. make depend
7. make
8. make install clean

Try this steps. It's the most easyest way to compile the kernel. If it's not working, post here the errors you get and we'll figure it out ;-)
Good luck !
Bye !