Yes, I had a sidekick that I cleaned up with ? Goo Gone (or maybe it was windex) because it had a couple of smudges on it. The thing gunked up like mad. It took a couple hours to pull it apart and rub off the sludge. If you don't get the catalyst rubbed off of the chassis it will continue to break down the plastic.

I'd recommend giving URC a call. To me, it would only be right to replace the chassis. I'm sure they're aware of it. I've only seen this on the 700/200's.