GData responded today with their dump-analysis. The culprit was the driver of my network card.
I use an Atheros on-board network interface on my ASUS P5Q maninboard and had used the standard Windows 7 driver since migrating to Win7 six months ago. No driver update was offered by MS since. I updated the network driver from the ASUS website and upgraded to GDATA Antivirus 2012 and streaming to my Samsung C-series suddenly works.
Problem resolved! Cudos to the GData guys.
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