I suggest downloading the "TH2" patch and trying that :D.
Seriously though, next time TH2 is on sale, give it a look see. I bought it back in the X2 days, since I didn't have the NI stuff then. Now I do have GR5 and it is nice, but I think TH2 is better. The interface is a little silly (overly visual) but the sound is great. Too expensive at their standard $200 price, but if there's another deal to upgrade on the cheap from the Sonar version, have a look at it.
Not that the GR5 problem doesn't need fixing.