I don't understand why everybody is discounting the fact that the disc itself may be a factor. We have all had experiences with a disc that does not come as advertised. I have a 163 pro beast that was freakishly overstable out of the box. I was carrying max weight champion beast at the time and bought the pro plastic hoping for a more understable counterpart.
If you want to know if it is you or the disc, hand it to an experienced player and ask them to test drive it for you. They will be able to tell you if you have a fluke disc or whether it is a simple case of it not being the right mold for you at this stage (maybe a bit of both).
BTW - after a year of using that beast for spike hyzers and big headwinds it beat into my most reliable driver. I have to wonder if it was a mislabeled as it flew similarly to a my max weight DX Starfire.