But first, the memory leak in my sense is the decreasing of program's free RAM after each soft reset. Even you are not touching your ppc, your free RAM still going down and hang up at the end.
In my case I primaryly noticed the service.exe size was becoming bigger and bigger from 200KB to 16+MB within few hours (possibly). The problem caused by windows live service. I still do not know any technical reasons behind but after I deleted some Windows Live registry keys, the problem has gone. Now is after my 2 days test, the services.exe has never gone beyond 1.6 MB. System is now very stable no reset required for days.
This might help some system having same problem, so I come here and share this. BUT USE IT AS YOUR OWN RISK.
Go into registry,
Delete the keys inside EXCEPT following,
Also, delete keys inside 'Plugins' EXCEPT following,
GOOD LUCK !