Pppoe server not work with pptp server active???

[appavito]

the situation is this:  4 wan with load balancing,  one interface for radius subnet + some interne services  + one  interface for pppoe clients.

i wont create one vpn between wan to radius subnet for control mysql and some other service  from my house, but when i enable pptp server  the pppoe server not work!!!  anything have ideas??? ???