i'm also getting this kind of problem. I've tried both kinds of sampling, changing texture size and nothing seems to work.
i get this
<img src="http://i35.photobucket.com/albums/d179/iloveyoumaryjane/1-1.jpg">
turning into this (note the corner)
<img src="http://i35.photobucket.com/albums/d179/iloveyoumaryjane/2.jpg">
i'm using the latest build also