Hi
Its due to your D008.dat file in the Data folder.
In this file the code used for RAF is as below which allows any ModeS code of 43C to 43F to be assigned to the RAF.
Old data:
RA,United Kingdom Mil,0100001111--------------
Take a copy of the D008.dat file and save it in a safe place in case of error.
You need to modify this line (i used notepad) by deleting the last dash after the last 1 and adding a zero in its place. This then sets the RAF to 43C only.
Open up the D008.dat using and change the line to
New Data:
RA,United Kingdom Mil,01000011110-------------
Save and replace old D008,dat in Data folder.
Becareful to only delete the one character and add one as extra or reduced characters may cause problems.
Hope this helps
Brian