Add / remove item generates javascript error

[JibutuFlavour]

If i add or remove item on the product details page Chrom's (version 18.0.1025.142 m) Developer console gives the following error each time:

GET http://mydomain.com/index.php?option=com_virtuemart&nosef=1&view=productdetails&task=recalculate&format=json&lang=en&quantity%255B%255D%3D1%26option%3Dcom_virtuemart%26virtuemart_product_id%255B%255D%3D625%26virtuemart_manufacturer_id%3DArray%26virtuemart_category_id%255B%255D%3D50
f.support.ajax.f.ajaxTransport.sendjquery.min.js:4
f.extend.ajaxjquery.min.js:4
f.each.f.(anonymous function)jquery.min.js:4
f.extend.getJSONjquery.min.js:4
$.setproducttypevmprices.js:89
(anonymous function)vmprices.js:26
f.event.handlejquery.min.js:3
f.event.add.i.handle.kjquery.min.js:2

The function itself works fine, but this error message bothers me. Is it just me?