Switching Off - Small Spinning Ring Is Still Spinning

When i turn the iPad completly off from the switch on top and then slide to shut down and after the little spinning ring dissapears after around 5 secs the device seem to be completly off...But when i decide to switch it back on say after 2 mins with the power switch on top the small spinning ring is still spinning and does this for around 5 secs again then goes blank, then i have to hit the power button again to start it up again, then the apple logo appears and starts to boot up.Has any one had this problem? Does it seem to be a software or hardware problem? Can someone try this with their iPad to see if it effects their deviceIt happens only say every 2 out of 5 reboots.