i have a strange behaviour i could not explain. from time to time the edge creasing of my entire mesh is reset to 0. i then found out by luck that this happens when i flip the edge of two triangles.
somebody knows what i can do to prevent all edge creasing values to be reset to 0 if i flip edges?
I noticed this behavior too. It also happens in earlier versions, or at least ever since edge creasing was introduced… Flipping edges seems to reset them… 
i think i found a simple hack to get around the problem of edge flipping, at last it works with me. instead of edge-flip i ALT-J, then CTRL-T. this should flip it. otherwise, try again. i noticed that the splitting alternates each time. 
. this way your creasing stays alive 8)