I did find on another site the same issue that I am having. The way 'around it' is to turn off the receiver, open FTlink, select update, pick the file and (at the same time) click open & turn on the reciever. Sound crazy & i tried it several times. DID NOT WORK!
Does the receiver on the menu screens say Digiwave? I think there were some files to turn your Digiwave into a Coolsat at one time. There should be a menu with version information somewhere. Wrong version sounds like the receiver software is rejecting the upgrade as it thinks the flash file is for a different receiver.