The bed squeaks...A LOT.  Here is how we fixed that.  Where the shelves sit on the bars we got some door weather stripping and put that between the shelves and the bar they sit on.  We also used 3 in 1 oil where those same square bars attach to the vertical support.  Shake the bed a little and listen where the squeaks come from and oil it.  No more squeaks!  Also, buy 3/4 inch pipe insulation for the rungs on the ladder...easy solution to the problem of the painful ladder rungs.