You actually don't need trace flag 3605. Just 1222 or 1204 is enough to write the deadlock info into the error log.
1204 puts the deadlock graph into the error log in text. 1222 (SQL 2005 or higher) puts the deadlock graph into the error log in xml.
On SQL 2005, you can also use profiler to catch the deadlock graphs. I still prefer the traceflags though.
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