Odd, they all run fine for me on each system I tested it on including the proxy one.
In the log you will see that that repair is ran twice, once under the current user and again under the local system. Did it fail on the local system one?
Reason why is tweaking_ras.exe in the files folder is used to run the cmd.exe under the system account and so if anything gets in the way or keeps that from running then the repair wont even run.
Shane