Can I do a HD upgrade on Rebug 4.21 without going back to 3.55? I have the original launch model (cecha) and want to do a HD upgrade. Seeing as there is a new rebug out and people say that you can go from rebug 4.21 directly to the new rebug 4.3 that was just released. I would like to take this upgrade opportunity to upgrade my HD. Does anyone see a conflict with doing this? Thank You for any advice on this matter.