I've downloaded and installed Dockrunner. Ran it with no issues at all. MIKRADLE still induces the multimedia mode with or without Dockrunner. So - at least in my case, it's not an incompatibility.
I would suggest at this point, especially if there is a store RIGHT DOWN THE STREET you hop over and let them look at it. You hope you don't need a replacement, but why would you want to keep a malfunctioning phone? They will probably replace it right there on the spot. They can move your contacts over, and you will have to download your apps again. I'd do this myself. I enjoy viewing my Droid displaying the multimedia mode while it sits on my MIKRADLE both on my office desk and home night table.
Good luck - keep us updated.
cuskit