You always have locking on updates, you will have locking on the select unless in one of the snapshot isolation levels.
Are you seeing blocking, or is the update just slow?
What's the entire process that the update is part of?
Got any triggers on that table?
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