As a mechanic in the industrial maintenous field for the last 20 years I've personally never had issues using teflon pipe dope.
I currently use it on a few fittings on the racecar and I've used it countless times on pipe fittings, joints while at work- some with crazy high pressure I might add, all I can say is that it was either not tight OR you didnt use enough.
JMP>Cp