After updating to IOS 8.0.2 on my iPad (v3) I noticed the text behind my on-screen keyboard did not scroll down and I could not see what I was typing. So for a quick work around I grabbed my Belkin Bluetooth keyboard which suppresse the online keyboard and used this.
A sudden thought this morning, what would happen if I turned off Bluetooth on my iPad. This I did and the problem went away. I then turned off the Belkin keyboard, not just disconnected, and turned on Bluetooth and the problem did not return.
It appears the iPad needed this extra shove to get going again.