We have an issue with the hyphen being removed from the URL when users click on the buy button. This causes problems with adwords as the Google assigned ID gets changed and we can't track conversions correctly.
The underlying code creates an array and it seems to be this function that is deleting the hyphen from the URL when the product page is created.
You can see an example of what is happening by using the following URL - [url removed, login to view]
The issue is when the buy button is clicked, the hyphens are removed from the URL when the item is added to the shopping cart. If you view the source of the product page, you'll see the link that is generated as <form name="cart_quantity" action="[url removed, login to view];id=test123456" method="post">
The OSCommerce version is 2.2 and the site has been heavily modified
Please get in touch if you can fix the problem.