Ok, Skimmer, I see exactly what you mean. I forgot that when I first put this effect on to my F18 about a year back, in order to get round the same problem I moved my Cabin lights (type 10) over to my Instrument Lights (type 4). That meant I could switch both my Cabin and Instrument lights on using the Shift + L keypress. But that of course isn't the default lights arrangement...silly me! LOL...my memory ain't what it used to be
OK. Now that you've jogged my memory, the following solution should be a good one.
Assuming you don't have any other additional configurations of your own in the [lights] section of your aircraft.cfg file, make it read as follows:
[lights]
light.0 = 3, -26.70, -4.00, 1.40, fx_navredm ,
light.1 = 3, -26.70, 4.00, 1.40, fx_navgrem ,
light.2 = 3, -49.40, 5.80, 8.50, fx_navwhi ,
light.3 = 1, -46.20, 5.90, 7.50, fx_beaconb ,
light.4 = 1, -46.10, -5.90, 7.50, fx_beaconb ,
light.5 = 10, -14.00, 0.00, 2.00, fx_vclight,
light.6 = 9, -40.0, 0.0, 0.0, fx_RCB_machenvlop,1
Now go to your Gauges folder. You should find a COP3 folder in there. And in that COP3 folder you should find a file called SonicBoomControl.xml.
Edit that file...
Wherever you see "LIGHT CABIN" and "TOGGLE_CABIN_LIGHTS" mentioned,
change these to say "LIGHT LOGO" and "TOGGLE_LOGO_LIGHTS".
Once you've saved those changes, start up your FSX and you should now have a working sonic boom effect, and your Cabin Lights switch should be working normally in the cockpit once again. (keyboard Shift + L will switch on your Instrument lights, but there's normally no keyboard shortcut for the Cabin lights unless you've made a key mapping yourself).
I've tested this fix and it works AOK for me and hopefully will for you too. But let me know if it doesn't and I'll try and help further.
Good hunting, sir.
- Voodoo