Don't use Task Manager to look at SQL's memory. It often lies.
In this case though it's probably right. 1GB for the buffer pool and 600MB for the non-buffer portion (thread stacks, backup buffers, etc)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability