trouble controlling stepper motor with L293D

I have recently bought a 28BYJ-48 12v stepper motor i am using an L293D dual h bridge and an arduino uno to control, My problem comes when i try to make the motor go clockwise, i have checked the code and my wiring and can find no mistakes.
the code and wiring diagram can be found here: http://www.tigoe.com/pcomp/code/circuits/motors/stepper-motors/

any help with this would be greatly appreciated.

So what problem would that be ?

sorry forgot the most important part it wont go clockwise

Does it stop ?
Does it go anti clockwise ?
Does it vibrate ?
And does it get hot(ter) ?

You are showing the instructions you used to build your setup.
If it doesn't work, assume you didn't do exactly what the instructions told you.
It will be an almost impossible job to help you if you do not show us what you've got exactly instead of what you think you have built.

it runs fine anti clockwise and it pauses for the 500ms but then it continues anti clockwise (this is when it should go clockwise). it works in both directions on my arduino mega but not on my uno and as far as i can tell i built them both the same way apart from changing the pins

sorry about being so vague, thank you for the replies

Then look for the differences between the boards (in hardware and in your sketches).

It's time to use some debugging tools.
One of those (and that is always available) is the instruction delay().
A program runs quite fast and it is impossible to visually follow every step of it.
So find likely fail-points in your program and build in a small delay.
Of course if you nailed your problem you will remove these delays, because debugging is about the only good reason to use delays.
Also consider the use of some LED's (in case they aren't already there) with accompanying resistors.
If you put them on the same wires that control your L293d, you can see what happens and which lines are HIGH and which are LOW at any given time.

My guess is you have crossed some pins after all, either by hardware or by their declarations.

Also check to see whether those pins you do use now, aren't used for any other purposes (like don't use pins 0 and 1 unless you really need to and know what you're doing).

i will give it a try thank you very much