To make all your pics visible:
1. In the Catalog panel on the left, select All Photographs.
2. From the menu, make sure Library > Enable Filters is unchecked.
3. Do Photo > Stacking > Expand All Stacks.
Thanks for the replies, I have been going round in circles for two days. Undoing the filters and Expand all stacks has cleared the problem.
Further I now realise that it was from before I started using Lightroom. I imported my Organiser File from Elements where I had the Raw files and the JPEG's stacked together.
Glad you got it resolved.