http://www.google.com/search?hl=en&lr=&q=sfxmem&btnG=SearchThats all I get when googling "sfxmem" (adding the .dll turns up nothing)
Kinda tells me you have a problem not easy to solve.
I suspect perhaps malware ... but not sure.
If no other replies shed light on your problem, post a HJT log to rule out malware influence, please.
http://www.bleepingcomputer.com/forums/forum22.htmlRead the pinned topics, and post in that forum ... new topic.