IMHO it does not matter too much where you will place "OK" button: to left or to right. It does not matter what kind of users visit your site (with hebrew or arabic languages). It does not matter what kind of software they use. The stats tell us that 55% of users want to see "OK" button from the right but if we will put it to the right, then the other 45% of users will be dissatisfied.
The best solution is to emphasize "OK" button (make it more prominent than "Cancel") and all the users will indicate "OK" button easily as more important and primary button.
Google and other companies use this approach in their software.
