After updating to OS X Yosemite the scroll speed of large maps is very very slow and stuttery with white areas occuring before finally redrawing. Was not a problem prior to upgrade. This is a 27inch Imac, very large screen. Reducing the map window does not make much improvement. Module in question is World in Flames 7.00, which is a BIG map with lots of counters out.
During upgrade to Yosemite had problems with some other java based apps (i.e. Chrome!) and had to upgrade to JRE 8.0 from oracle.
Suspect its a java window redraw problem. Any suggestions on JRE required or other tweaks. Was not a problem previously. I have a mac airbook and has not gone to Yosemite and maps scroll fine for all modules.