Well at first I thought it might be my Laptop as I installed WinDVD 10 on my main system and it played an ISO, but when I copied over the ISO's from my laptop to the main PC it does exactly the same, comes up with unsupported media and crashes. The same ISO's work fine in PDVD and TMT as well as working fine when written back to BD-R and played in my settop player. Looks like WinDVD 10 is a bit unstable