Custom OnePageCheckout Payment/Shipping problem

[JohnSouth]

Hi

We're developing our own OnePageCheckout and have made many changes. (version 7.0.3)
We're getting a problem with the interaction of the shipping method selector (a radio button list) and the payment buttons that are on the same page.

If I click to change the shipping method, and then complete the credit card details and click the payment button, the card details are cleared and no payment takes place.
Conversely if I click on the payment button with no CC details entered I get the validation messages, and if the next click is on a shipping radio button it has no effect.

My theory is that there is a routine somewhere to stop double clicking on a payment button, but it is being invoked by the shipping buttons as well.

I'm having trouble tracking down the javascript/Ajax functions involved and would really appreciate some pointers on where to look.

[mazhar]

Well a wild guess is to check the OnClientClick event processing. In code/ascx file check code against OnClientClick button to figure out the problem.

[JohnSouth]

Yes, thanks, but there's no OnClientClick on the buttons in question. I've now tried creating an alternative button, with no onclink code, and still get the problem, so I think it must be in the form onsubmit code. My problem is finding where it's specified. The source code of the displayed page has a WebForm_OnSubmit() function but I can't fine it in the project code.

Any guesses (wild or otherwise) would be appreciated.