Paul:

Try this. Open "prefs" in RB, go to screen #1 ("General") and see if the second to last box ("When resizing....") is checked. If so, uncheck it, and then experiment with expanding and contracting the screen.

I think something has changed in the latest implementations, but it's hard to figure out.

Good luck. (Alternatively, new glasses, but these days, new monitors may actually be cheaper than eyeglasses.)

Brad -- My FAWM