Mouse isn't showing where the cursor is?

i know this is hard to explain but if im playing something that needs java or anything for example.. runescape, when i hover my mouse over the log in button its like a centimeter away and highlighting the create an account button so when i want to click something i need to go a few inches down from where it actually is.. its like its not calibrated if you understand me lol. I've renewed my flash so idk what's wrong i cant play this game on firefox or chrome coz i have a mac so i can only play it on safari or camino (which does the same) any ideas?.. i cant find a java update for mac so maybe thats it so if you think thats it maybe u can give me a link to the latest java.