Register play store after reboot on wifi to test if working
Your kyros is now a galaxy s3 this seems to be best device for play store downloads.
Now backup and save all your data.
Do a factory reset. My 1125 ics 4.1.1 is german image.
Reenter start info. Reregister using WiFi for play store.
Play 3.5 should now work without any faults or problems. Installed 3.8 play store and all is OK even after reboot
If errors happen clear play app data and reinstall app.
My kyros 1125 is 3G model ics 4.1.1 updated from German website. With root and play store now.