Hi John,
I have attached the complete .ini file for you to analyze and I am using version 7.4.5.
The way I am assigning the keys is as follows: after selecting "profile specific?" , I select the desired key, check box "select for preset" and in "find preset" I choose the desired assignment, confirm and then ok. For example, I am assigning the F9 key to the preset "PMDG B737-7 LIGHTS TAXI TOGGLE" but in the .ini file it appears 520=120,8,P,0 -{F9: Press=Preset Control }-
Note: When I am creating the assignments and FSUIPC7 and MSFS are open, everything works perfectly, but after closing both everything is lost as if it was not writing to the .ini file
FSUIPC7.ini