Cheers Wayne, it's a bit of a bugger isn't it, even more so for you with your heatsink not allowing the side panel to be put on.
I agree, it probably is the Motherboard sitting higher, as I fit my old Motherboard and back plate in the P182 and that fits perfectly, but having a second back plate to modify is my only solution as I don't feel like sanding the Motherboard stand offs down and trying to get them all the same height and straight, which I think is the only other option. I don't want to change the Motherboard either as I really like it and it's working perfectly.
I'm not too fussed about the eSATA to be honest, but I want to use the 2 USB ports and my Keyboard is a PS/2 connector, which I've had to push a bit harder to get it into the connector, not really happy with it but atleast its working.