Answer to fist question: It might be that the drive simply doesn't work with the drive, but there are some things you can try. First thing you can try is using the latest version of GX and trying to use different cIOS to load GX (you can set which IOS to use as default, which is also used to load GX). Second thing you can try is going to the manufactuers site and see if they have tools for your drive that allow disabling energy saving features.
Answer to second question: This is not true. Desktop drives can be placed in an enclosure and be used for back-up loading. It could be that the enclosure is incompatible, but it could also be the drive itself. Again, you could try using different cIOS to load it, but it is unlikely to help.