I know that with my devices I sometimes had to reflash several times due to various issues. Maybe try reflashing a time or two.
If it still happens you could perhaps see if Google Play can be stopped from updating itself. Below is a link I saw. You need root for this, it seems. I haven't tried it myself, but 3c Toolbox lists the service that is talked about in this link.
http://android.stackexchange.com/que...cally-updating