Go ahead and laugh at me, but I wasn't paying much attention during a software update a month ago and allowed "Apple Pro Apps Update" to install. I paid it no mind because I don't have FCP X on my machine, nor plan to. So, I didn't read the thingie that said "for FCP X and Motion 5 bla bla bla". I realized it after any of my video related apps simply are crashing like mad and my video card is freaking out since the update. I'm running OX 10.6.8 and re-ran the newest NVidea drivers and still have issues. How the bleep can I get this update and all its evil sludge off of my Mac?
FCX and Motion 5 are updated through the Apps Store.
As long as I know, the only update supposedly for FCX and Motion that can be installed in FCS is the "Codec Update" and that shouldn't harm your system at all.
Try to repair your permissions.