Configuration overview

General settings
TCP Port:1723
Encryption settings
Encryption:Stateful MPPE 128-bit
Misc settings
LCP echo interval:60s
MTU:1400 bytes
MRU:1400 bytes
Assigned DNS servers
DNS 1:
DNS 2:

Connection drops

First, try disabling stateful encryption for your PPTP connection. If the connection works afterwards, you are fine.

Second, there is a chance to get a stable connection by lowering the MTU. For Linux, please read this FAQ entry.