I've been intermittently having the same issue with DirectRT. Whenever Medialab calls for DirectRT to load, it takes approximately 3-minutes for it to start. I'm running WinXP and ML/DRT 2010. I have tried different screen resolutions in the style files, and have has the same issue. I just tried loading a study directly in DirectRT (i.e., not using Medialab to start it) and didn't have the problem, but because this is an intermittent problem, that might not be diagnostic.

Also possibly related, often, but not always, after running DirectRT, the monitor resolution stays changed to the DirectRT settings.