Make sure your browser is zoomed to 100%. If it's at 100% and you still have the problem, post a screenshot so people can see what you're talking about.
You mentioned in another thread (which I deleted to keep everything in line) that you have this problem with most of the games, except for the MMO games, on all computers and on all browsers...
It could be that your browser settings are indeed zoomed to a percentage above 100%, like Patrick2011 mentioned. What you need to do is try to set the zooming back to 100% by pressing "Ctrl" + "0", which will reset the zooming to 100%.
I'm pretty confident this solves the problem, but if it does not, please notify in this thread and we can have another look at it, ok? =)
