It wouldn't surprise me at all if that was the case. I've had power adapters cause all kinds of problems.

I tried using some cheap after-market adapter on a Super Nintendo once, and although it claimed to be of the proper voltage, it didn't supply enough power and caused terrible problems with the graphics and rendered some games unplayable. Yoshi's Island would just keep repeating the title screen over and over, it was weird.

I suspect you may be having the same problem: Not enough power. Some consoles aren't so finicky about this, but the CDX probably needs every bit of the 1.5 amps the original power adapter gave it, and the model 2 adapter you're using isn't even one amp.

Definitely get an original adapter.