Magento v1.4.1.1 - Shipping cost doubled in Grand Total

I'm running Magento v1.4.1.1 and the shipping cost is being doubled in the Grand Total on the shopping cart page as well as within checkout.

This happens regardless of whether tax is involved or not and regardless of shipping method (i.e. flat rate, FedEx, UPS).

I have searched the Magento forums and found that others are having the same problem. Unfortunately there are no replies with a resolution.

Would anyone here happen t开发者_运维问答o know the cause or how to resolve this issue?

I'm not sure if it helps, but I had the same problem when I did multiples

$quote->collectTotals()

It was on a custom code, but maybe you even don't have any?

An installed module caused a conflict and thus the problem. Once the module was updated the issue was resolved.