All I can see about 260 on the forums is that it causes even more slowdowns
But I can try it.
Though theres a chance KDE has worked arround this particular bug. It seems driver makers don't seem to realize that things might want to cache a lot of pixmaps in the graphics card. So KDE's Oxygen widget theme has had to hack in a way to cache less. Hopefully the change will help. But I'll test 260 first, then the oxygen changes.