I alway carbonate outside my fridge at about 18 PSI, and I never attach
a tap. After about two weeks, I detach the keg and put it aside. I've
never had a problem with leaking beer or gas in over six years.
What brand of kegs did you experience this with? Do you use keg lube on
the poppets? I've seen people use the wrong poppets on kegs, and make
them work for the most part.
If kept clean and lubed, they should not be a problem.
--
Dan