Hi there. Could anyone kindly give me any advice or help regarding the following issues i have encoutered since purchasing a second hand Tokina 12-24mm lens.

I am getting the following error messages on my eos 50d and 350d body whilst using the lens.

350 D: err 99 flashes up when on landscape, manual & AV settings.

50D: Err 01 Communications between the camera and the lens is faulty. Clean the contacts. This occurs in landscape, manual, AV and C2 settings.

It would appear to be a lens contact problem??. If so can anyone recommend how to clean the lens contacts. Though i have inspected the back of the lens near the contacts area appears to be clean.

Their was some small dust particles near the contacts on the 350 d which was cleaned as soon as i spotted it however i continued to get these issues after.

I am not getting any of these issues when using my other lens with the 50 and 350 bodies only when using the Tokina in the above settings do these error messages occur.

If i cant over come this problem can anyone also please recommend a Tokina lens camera repair outlet in NSW or Sydney to please if neccesary.

Thank you in advance.