for some reason whilst im driving i can turn the cruise control on by pressing the on button and it shows on the dash that its on, but when i press the set button it doesnt want to set it just wont connect.any ideas?

Check your brake lights and brake switch.

why would they interefier?and how do you mean check them?

Because they're wired to the Brake light switch.
When you depress the pedal, the cruise cancels.
A lot of people replace the Brake light globes with the 'WRONG" type. They require 'twin' element globes.
Get someone to check your brake lights work when you depress the pedal.
Also turn your parkers/headlights on and test them again.

You also need to be going above 40kph for the cruise to become active.
You also might need to check the throttle cable going from the cruise module

If all above are fine then you may have:
A faulty brake safety switch located on the brake master cylinder.
Simply undo this plug, short the contacts out and try again.

i had this problem but only when the parkers where on the bloody filements fused together sending power through that particular switch

Exactly!

That's why i stated to test brake lights with parkers on.

The dead give-away is when you hit the brake pedal, the dash lights illuminate.