Error preg_replace() after checkout vm 2.0.6

[nvsdesign]

After I have confirmed my order, I get the following message:

Warning: Wrong parameter count for preg_replace() in /home/nvsdesign/domains/nvsdesign.nl/public_html/klanten/plottershop/administrator/components/com_virtuemart/helpers/vmfilter.php on line 778

What's the problem and how can i fix it?