This needs bumping, or needs more attention atleast.
Same problem and all.
Older games will end up giving rundll32.exe an entire 25% of my cpu (4core) when I double click the exe (Older games including max payne 2, ut2004, silent hill 2 and even quake 1 etc and many more...)...thats all that happens, you can watch this in Task manager...but the game doesnt start, you double click the .exe again THEN the game starts, 25% on the 32bit game 25% on rundll32, awesome thing is you can just end rundll32 and the game runs absolutely fine regardless...
(I have a theory that its AVG on access scanning or something doing this)
But awkwardly enough.
Modern games such as Bioshock, Fallout, Crysis: warhead and Empire total war, all stick to respective 32/64 capability, with no fuss with rundll32.exe
Not like DirectX could have any qualms with rundll ?
Maybe even the gpu drivers
Although I cant remember when this problem started, I might be able to say it was recent (And within that time I have not really done anything too significant to cause this), but I can definitely say I never had this problem a few weeks back...