However, when orders go from VirtueMart to vTiger as invoices, the list of products is blank. I wasn't sure if this was just an issue with the free version, so bought the paid one, and this issue is still there. I emailed the author a couple, and there was no response.
My version numbers are, Joomla! 2.5.9, vTiger 5.4.0 and VirtueMart 2.0.18a