With the newest edition of Samplitude no hang, with the latest edition of Sound Forge no hang, with the latest edition of WL there is always a hang. I too am using an RME card with the latest drivers.
As you can see by my other posts I am having a lot of problems with WL at the present time. WL6 was always so stable but it seems that once WL was ported over to the Mac it got very finicky with certain PC hardware. It might be interesting, if he is willing to share, to know what PGs computer has for hardware since he seems not to have the problems the rest of us are having.