UC Variable price is not replacing the default sell price.

UC variable price is a wonderful module. But there are some difficulties while using it with other modules. The default sell price is not replacing with price the customer entered. specially it is a problem when calculating commission upon the payment. In the shopping cart the price is displaying properly. But when I use it with ubercart market place module where the sellers get a commission on sell price, the variable price is not replacing the sell price while calculating the commission.

Please suggest any solution