Hi there! Love my Retina iMacs Display to pieces, but am suffering from several strange phenomenons where I cannot really pinpoint any causes ... 1) Massive Lag with expose. Takes several seconds to show, ultra-laggy animation that consist of maybe one or two steps and takes forever (well, 2-3 seconds sometimes) 2) Strange sound from external speakers on wake-up. Like four fuzzy beeps. 3) System volume changes by itself on wake-up from sleep 4) Menu bar shows pixelation when two screens are in use and whenever changing from active screen to inactive one. 5) Open-Save-Dialouge sometimes takes 10-15 seconds to work (beachball in between) and "Open with ..." context dialogue also takes 10-15 seconds to work. If I do it again in the next few minutes, it's much quicker. After a while, it'll take very long again. Anyone with similar / same problems and any suggestions on how to solve any of this?