Login failed for user 'sa'. Reason: Server is in single user mode.

SQL Server 2005 SP2 2005.090.3054.00

I'm trying to move master/model/msdb to a new spot.  I restart SQL
Server in single user mode with the "-c;-m;-T3608" startup params.

When I try to connect to do the detach, I get:
Login failed for user 'sa'. Reason: Server is in single user mode. Only
one administrator can connect at this time. (Microsoft SQL Server,
Error: 18461)

But no one else is trying to connect....????

I have stopped all other services other than the main MSSQLSERVER server
instance.. same result..

Any ideas appreciated..

aj