>After verification, this can only apply on a INNER JOIN clause. I cannot use that syntax in a WHERE clause.

You're right, I see that this is a table hint
http://msdn.microsoft.com/en-us/library/ms181714.aspx

Did you read the blog I sent you earlier in this thread (about possibility to experiment with LOOP JOIN)?

If you post your query and how many records each table has (and which indexes), it will be easier to discuss the problem.