White Screen when changing order status in admin

[iamdasboo]

Hi there

I have a site using Joomla! 2.5.22 and Virtuemart 2.6.6. I have a Sagepay payment gateway installed. Payment seems to go through fine and all details are showing in the admin side. Emails are also being sent to customer. However,  when I have click on the "update order status" I am presented with a white screen and URL of ../administrator/index/php, no matter what status I am updating the order to. Notify Shopper is also selected but nothing is received.

Any help on this is much appreciated.
Thanks

[jenkinhill]

For white screen:  http://forum.virtuemart.net/index.php?topic=117042.0

Also http://forum.virtuemart.net/index.php?topic=118683.0