>It came back today. I got it three times. I really do not know how to adjust that to avoid this deadlock problem:

I'm not sure what's causing the lock, but you can add the NOLOCK hint to your query. That will use the minimal amount of locking. The data might slightly be out of date, but it's still valid.

DECLARE @NoMember Integer
DECLARE @LastAccess DateTime

SET @NoMember=12985
SET @LastAccess='2009-02-13 11:02:33'

SELECT Member.Numero,Member.Nom,Member.Prenom,Member.LastAccess
 FROM Member WITH (NOLOCK)
 WHERE Member.LastAccess>=@LastAccess AND
 EXISTS (SELECT 1 FROM Monitor WHERE Monitor.NoMember2=Member.Numero AND Monitor.NoMember=@NoMember)
 ORDER BY 2