Now that XRandR 1.2 is working so well I change resolutions a lot (between my laptop display and the larger one sitting on my desk) which brings an old favorite GNOME bug to the forefront for me: Applets on the right of a panel change positions and order when display resolution is changed.
My personal take on this is that the panel should not touch the position or right_stick settings of an applet at all but should only try it's best to interpret them in a sane way. It seems to be changing the positions when the size of the panel changes, probably trying to do the right thing.
The possibility of treating the gnome-panel more like Firefox treats it's tool bars, with all positions being relative and fixed and variable width spacers, is also reasonable. In the mean time I've written a script that resets the broken positions and reloads the panel. This reveals bugs in applications that don't handle a reloaded notification area (including network-manager-gnome) but I can just restart those as well.