ive heard that you need some good strength in your shoulders before doing arm jumps.
can anyone give me a few exercises to help me on this??
bear in mind im 13 =]
thanks

saut de bras translated means arm jump.  also known as a cat leap.

what chris said.

neil, i think you may be confusing ideas as far as arm jumps go; the main muscles that will absorb your momentum in an arm jump are the pulling muscles: arms, back, posterior shoulders (to be vague). Where the shoulders really come in is when you do an arm jump that is too big, and you aren't able to properly lower yourself through the catch. That's when you kind of wrench your shoulders, and trauma can be built up from doing this too much. So really the solution isn't stronger shoulders, though strengthening your pulling muscles will protect your shoulders.

Correct me if im wrong (as i know you guys will anyway    )

For the cat leap, or arm-jump, the legs should be the first to absorb impact. You land on the wall with your legs first, and then absorb the rest of the impact with your arms. If your approach to the wall isn't correct in the first place, then maybe the remedy is to correct the movement. Then if other problems persist, we tackle them from there.

Also, i'd like to know if your problem is a.) performing the cat leap from a lower level surface jumping up to a wall or b.) hanging from one wall  and then leaping onto another wall

This depends....

If you ever did a cat leap out of desperation you know damn well that your body can slam against the wall while your arms take all of the load.

Also, sometimes the surface is slick, and your legs slide down, making their load bearing capabilities less.

If you are doing PK and can't support yourself in a static hang or do at LEAST 5 pullups, you need to work on your strength before training seriously.

Arm circles.. for warmup maybe. Wings with DBs are ehh. Not a very useful exercise.

Rockclimbing/pullups + dips or just muscle ups in general should be a traceur's staple exercises for obvious reasons..