i really hope rtv is wrong about the patch
what it is supposed to do is to avoid blocking the Message Queue by doing as much as possible in a second thread and not in "WM_IDLE". If the WM_IDLE message does not return within a certain time, vista thinks that the process hangs. and because all of the time intensive stuff (building the directshow graph, reading tv-epg-data, ...) is done within this message handler too, this happens quite often.
i knew beforehand that this patch will break a lot of stuff, because many things don't like being called from different threads (you just gotta love MS+.NET for that). this is e.g. the case with visualizations in My Music , and seems to be something similar with My Alarms. and it is the reason why i never tried commiting it. this can only be really fixed by re-designing a big part of MP --> hence i wait for MP II which (hopefully?) does not suffer from this issue.