Dell Customer support can be so frustrating.  My motherboard on my XPS 710 failed.(Solid amber light even after removing all connections).  I phoned an order in for a replacment motherboard for my XPS 710.  It seemed like they were able to order it but I never did get an email with all my order information nor was I able to call it up on the computer.  I phoned again and gave them my email and they said the order was in production.  I asked them again to send me the email, but again I recieved nothing.  The motherboard came in yesterday.  As I was attempting to do the replacment I found out that it is not XPS 710 board (Connectors on back did not match up with holes, Front panel  I/0 connector was different on the motherboard).  So I called up and sure enough they sent me an XPS 720 motherboard and they are telling me that is not compatible with my system!