I successfully programmed an MX-890 with a dozen devices last week and am in the process of final final testing and tweaking.

The software does appear to have issues with moving buttons around between pages on a device, including the surprise white background you mention in post #1. Also, buttons may disappear or behave erratically. If you delete a button, you may not be able to add a new one. Sometimes you can't swap button positions on the SAME page. CCP can often crash once you are in the midst of these issues.

The workaround is laborious duplication of buttons and then copying and pasting between pages.

Eventually, you can figure out what works and what to avoid. The end result is a very nice remote IMO.

The background changing tips above are very handy, as I didn't find some of that.

Now I'd like to figure out how to import a couple of the devices from one 890 into another 890 (or other MX). I see the "Transporter", but can't get it to see anything but the Main pages of a saved 890 CCP file.

Edit: OK --- I figured out where to import a device, but now I can't properly link it to a new device button. I can manually add a new button on a Main page and a jump-link to the imported device --- but I don't know if that really creates a proper link. (With devices created through the program tab, the software is aware of the link, so that deleting either the button or the device warns you and deletes both. This does not happen with an imported device and manually created device button.)