lost most banks of scenes and chases dmx 192

I was trying to add a new fixture to my scenes and chases and once I got to bank 5 I noticed everything was black. I continued all the way thru bank 19 and they were all lost.
I had four chases programmed and only chase 1 has any scenes saved.....only thru bank 5 obviously.
Is this a normal occurance .....is there a way to back up this controller.....anyway to retrieve lost scenes....any help is appreciated