Video tearing in XBMC Eden

I am on Win 7, 64 Bit, XBMC Eden, No graphics card / hardware acceleration.

Here is the log file. http://xbmclogs.com/show.php?id=6182

I noticed starting yesterday that ALL movies exhibit tearing... sometimes a LOT of tearing. I believe there was a windows update in the last week or so and this appears to be related but I cant find out what exactly. The movies are actually unwatchable now..

I have attached the log files, starting with line number 1683 onwards (dark knight).

Any pointers are appreciated.