I updated my test machine to rawhide. Using the following pptp related packages.
NetworkManager-pptp-0.7.0-0.10.svn4027.fc10.i386
pptp-1.7.2-3.fc10.i386
pptp-release-4-2.fc9.noarch
pptpconfig-20060821-1.fc9.noarch
I tried to connect using NetworkManager and failed at about 18:13.
At 18:18 I tried pptp-client and succeeded.
At 18:29 I tried NetworkManager again, this time with MPPE on (which
I had forgotten the first time) and failed
I have attached the relevant portions of /var/log/messages