error: You must specify at least one recipient email address after order confirm

[muldeer]

using VM 2.0.18a on joomla 2.5.8 on PHP 5.2.17.

The error "You must specify at least one recipient email address" comes up after a customer confirms an order and NO email is send to the vendor.
- The registration email is send and received by the vendor
- The ask a question email is send and recieved by the vendor
- When you change the order status in the backend a mail is send to the vendor
- the email adres if filled in on the shop/vendor page and I looked in the database and the field table  xxx_virtuemart_vmusers, the user id has  a "1" in both virtuemart_vendor_id AND user_is_vendor
- tried smtp mail same problem persists

So only the first email to the vendor is missing the the warning pops-up. Any ideas?

Erik