This message is sooooooooo annoying!  This is a bug in QuickBooks that needs to get fixed.  We've been dealing with this for awhile now and nobody seems to know how to fix it.  When I go into Sales Order Fulfillment Worksheet to click on the orders that I have entered and want to send them to the pick/pack, I get these error messages several times, like 10 times for 20 orders.  It says, Looks like another user is working on this sales order.  Try again later."  There is nobody else!  It's so annoying and needs to get fixed.  Anyone?