Two SELECT queries deadlocking each other

I am using SQL Server 2005.  I am running the deadlock graph in SQL Server Profiler and trying to track down the cause of the deadlocks I'm seeing.  This one is baffling me.

I see two instances of the same SELECT query in deadlock.  I have attached a screenshot of the output from the deadlock graph.  When I hover over each of the circles I see the same query.  It looks like:

SELECT pw_id AS cw_id
FROM pw
WHERE pb_id = @pb_id
    AND m_id = @m_id

1. why are they both getting X locks?  they are just selects.
2. how can I fix this?  I could try using WITH (NOLOCK) but I still don't understand why it's doing this.
deadlock.JPG