The iso I burned won't play??

Ok I downloaded Virtual Tennis 2 from a psp network & it completed burning 100%. Alright I downloaded Mortal Kombat Gold & Sonic Adventure 2 & they loaded with no problems on my dreamcast. Everytime I load Virtual Tennis 2, this Echelon screen comes up. I hit start to play the game but it goes to the menu screen, you know the one that comes up when you don't have a cd in your dreamcast. I'm trying to figure out how can I get it to run. If anyone knows the answer, please help thanks!