FSX ADE compiles but no show in FSX

Hi all,
This is driving me up the wall and down the other side. I am tidying up a uk2000 airfield, the parking spots are being turned about and i am adding another GA parking spot. I have also added visable markings to the main runway. Nothing fancy. After fault finding with no errors i save the project, then compile, no problems here.

I have switched OFF the default .bgl file in uk2000 scenery and replace it with the .bgl one from ADE project. After making sure that the library in FSX update's, the addon scenery box is ticked, and the relevant area is added, i go fly to find the compile has not been done, parking spots and runway are the same, and no changes.

The frustrating thing is that i did the same thing to another uk2000 airfield not long ago and it worked fine, but somewhere along the line i have messed up, and i can't figure it out. It seems that there is another file somewhere stopping the details of the compile happening.

I switch the default file back on and the field loads and displays no problems.

Can anyone put me out of my misery?