Getting "If a bundle is selected as an existing product, you can't change it to another value" error while update product bundle price by Webservice

Hi All,

As per the client requirement I am trying to update product bundle price by webservice. But I am getting "If a bundle is selected as an existing product, you can't change it to another value" error while update it. Same code is working fine if I update single product. Any idea or work around for this situation ?