Thanks Mike thats really useful.
Ok I can see that there is a FIRR Database master file in the correct folder with the correct date and this is the one that the programme is now picking up ( its only 1KB?)
In the subfolder I have the rogue file - now being ignored but with a 22/03 date on it so presumably it was created sometime ago.
The rogue gedcom has todays date so im guessing that it is a result of my cackhanded messing today.
All is well now and I know which are the rogues and can be got rid off thanks to your advice but I will report to Calico Pie as you suggest.