mppe kernel compilation doesn't work

[Ferenc Tamas Gyurcsan <gyurcsan@ttlc.net>]

Hi everybody,

I'm running potato r0, and I'm having compilation problems when I try patching
the 2.2.17 kernel with mppe patches. Could somebody point me somewhere how to
do this? ppp.c doesn't want to compile . What I did was that I downloaded 
a mppe tar.gz from  http://merced.needsabeating.com/pptp/. And the compilation
says:

gcc -D__KERNEL__ -I/usr/local/src/ppp-mppe-2.3.11-9/linux/kernel/include
-Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -fno-strict-aliasing
-D__SMP__ -pipe -fno-strength-reduce -mpreferred-stack-boundary=2 -m486
-malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=686 -DMODULE
-DEXPORT_SYMTAB -c ppp.c
ppp.c: In function `ppp_receive_frame':
ppp.c:2171: `CI_MPPE' undeclared (first use in this function)
ppp.c:2171: (Each undeclared identifier is reported only once
ppp.c:2171: for each function it appears in.)
make[1]: *** [ppp.o] Error 1                                                    

I also tried another solution I found, what is detailed in 
http://www.moretonbay.com/vpn/releases/HOWTO-PoPToP.txt, 
but patching the kernel that way doesn't work either. Can somebody help me?

Thanks,
Ferenc