Andrew:
The root cause of the problem turned out to be the new Synchronicity
menu. They are using a graphic instead of text for the pull down menu
heading. The graphic height was larger than the text height so each
time one descended it would first make the menu the height of the text
and then make it bigger to allow for the graphic. When it made the
menu bigger it redrew the schematic or layout as it was resized
slightly and made it look like the window bounced. The variable to
turn off the Synchronicity menu graphic is:
dssShowSyncIconOnMenus=nil