Ok ther was an failure in vm´s payment class /administrator/components/com_virtuemart/classes/payment/ps_payment.php i haVE FIXED it with this manuel...

forum.virtuemart.net/index.php?topic=85136.0

thanks a lot,
the pdf component is working great.
greetings to the seycelles.

Hello evrybody there is an problem in vm checkout step number 4! the check out thank you page is white when the "VMInvoice Autorun plugin" is activated.
Please Help!

joomla 1.5.23
vm 1.1.8