You were always Zeus' Favorite!
My channel: http://youtube.com/user/czeuch
I experienced this as well... just changed to Ares after a few seconds even though I had Hades selected as my allegiance. Just select a different item in your abilities tab (then change back if you want to the item you had previous). Worked for me; some reason that stopped it from switching allegiances and I was fine for the rest of the time I played; ppl have been having bugs with the new patch already.