Cubepoint checkout problem

I've encountered some bizarre issues after I activated cubepoints to serve as the currency in my online store. Occasionally, once you add an item to the shopping cart (i.e. an item that "costs" 1000 points), the transaction cost resets to 1 point before the checkout takes place.

It doesn't seem to occur with every transaction, just intermittently (which is more troubling).

And I've checked, the transaction resetting to 1 point occurs even if the user has ample points available to make the transaction...

Any advice would be greatly appreciated!