pptp VPN connections fail with 3.18

[Jan Niggemann]

Hi all,

my pptp VPN connections fail when using 3.18 while they work fine on  
3.17, openvpn connections work just fine on 3.18.
I'm running Debian Wheezy 32bit on a IBM T400, my kernel configs are here:
3.17: https://gist.github.com/2974aa489986d6fc26e3
3.18: https://gist.github.com/8f0c4d4b52cd63bbc053

I can't see the difference, can you experts spot the issue or please  
help me to find the issue? What other information do you need?

Cheers
jan