I had the same issue. To resolve,the problem , log into iCloud and reset photo stream ( I realize that you have probably already done this, but I would do it again to be sure) . Next is to go into settings and turn off photo stream. At the prompt to delete, choose yes. Next is to reset you pad. Hold the power button down until you get the slider bar. Use the slider bar to turn the pad off. Then power the unit back on.
Now check to see if the photos are still there. If they are, repeat the above process one more time.
This is what worked for me. After the reboot, the photo stream pictures were gone.
Let me know if that does the trick.
Greygoose