timeout sql server on a fast query

I'm 100% sure that this question is a duplicate but I searched for a few hours and I didn't find anything.

My environment : windows server 2003, sql server 2005 , .net 2.0 (c#)

My problem :

When I run 5 request in the same time , one 开发者_如何学JAVAof my stored proc raises a time-out.

If , during the period the 5 request are waiting, I run in Management Studio, I try to call this stored proc with the same argument, I get my results in 0sec :)

I tried to see if I have too much connection opened but I can't see anything in activity monitor (I can see 14 item with "awaiting command").

So what is my problem ? I think it's a configuration missing , if it is, can you explain me how I will choose the value of this configuration.

Thanks

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You can also try altering the isolation level of the select statement in the SP using a table hint.

For instance:

SELECT col1, col2, col3 FROM Table1 WITH (READUNCOMMITTED)

There are several other isolation levels but READ UNCOMMITTED is the lowest and will read from a table that is exclusively locked. The downside is you can get dirty reads.

If the issue is with locking, this might help.