If he works better without fightclass, edit your fightclass and try to put 'false' at spell setting "Lock frame when checking the conditions" (on all spells).
Try also to reinstall your video card driver.
Hello, can you share your log file when you get this problem.
For your fightclass, check in existing fightclasses if any have implemented this: http://wrobot.eu/files/category/17-rogue/