Pricing error using custom fields

[ausfiero]

Hi, we have an unusual problem. When adding a custom field to a product for say size for example, we set the correct size and extra price. The price displays fine on the front end but when it is added to the cart the extra value for that size is deducted instead of added. We have tried plus and minus signs and multiple variants but no matter what the cart takes the value off.

We are using one page checkout but even disabling that and using the default cart gets the same result.

Virtuemat 3.0.9
Joomla 3.4.1

[jenkinhill]

And with Beez default Joomla template?