fastuserswitching.exe Trojan?

My nod32 is saying that fastuserswitching.exe is a virus and when i try to clean it or delete it it gives me an error... is this a false alarm or do i really have a virus? anyone else having problem with this?

 

Could you post the relevant record from the Threat log so that we know the full path to the file as well as the whole threat name?

 

9/29/2009 2:07:35 PM Startup scanner file c:\windows\system32\fastuserswitchingcompatibility.dll a variant of Win32/Fusing.AA trojan error while cleaning

 

Anyone can help?

 

It's a trojan, refer to the following link.