It is only partly the main alloying elements that can cause PWHT problems, but the microalloying elements, such as V, Nb, Ti, and B that exacerbate the PWHT embrittlement/cracking problem, as well as the processing route. TMCP (thermo-mechanically controlled process) steels have their own set of issues. A lot of whether the T-1 (ASTM A514 variety) type steels will crack on PWHT depends on the part geometry (restraint), welding procedure, etc.
Here is some more info on A514 steels made by ISG
http://www.intlsteel.com/PDFs/t1.pdf