Comment 4 for bug 619161

I have solved the problem, well almost.

It seems that the "portable players MTP" plugin for rhythm box is some how affecting the tablet, although I don't know why, if I disable it I can use the tablet and rhythm box at the same time with no issues.
Although this doesn't really explain what's going on, I'm guessing it's something to do with the way the plugin detects devices, but I'm not sure, my knowledge of this sort of thing can be written on the back of a postage stamp :-)