Make changes to product options in the cart without duplicating the order

[crn]

Is there an extension to VirtueMart that will allow the shopper to...
...choose a product and options
...place it in the cart (or temporary file)
...add or change the options
without duplicating the product quantity

I have run into the problem of adding a whole new product while using a different software application. I have tried out the VirtueMart demo and have seen the same issue. Do any of extensions fix this?