It has nothing to do with cache... unless that's some kind of RoundCube level cache I'm not seeing.
I've emptied the browser's cache hundreds of times, even going to far as to clear private data, nada. The problem is infrequent in FF, but when it happens it's persistent (e.g., getting rid of it is impossible). IE has no problem with it.
As I said, when it happens everything goes screwy... the panel is dragged all the way to the top of the page, the DEL button and dragging behaviors don't work, etc. Basically it's as though the loading scripts ran into a wall and a bunch of stuff (rich behaviors specifically) didn't get initialized.
Very annoying.
Thanks,
Rick