(Assuming your themes use it) check the docs for the module jDesk for a recycleOnRezChange setting. I hope that would work, as it would be a change in the resolution. A recycle is overkill for theme layout however--if this does work, theme could possibly be modified to have a script merely reposition/resize things (faster than a recycle as it doesn't have to reload things from disk) using the module systemevents-0.1 to detect a resolution change.