@N3wton:
Thanks.
I've tried what you said, but BlueGUI still won' work. I'm on U7.4 of DBP and Windows 7. I've tried every compatibility mode as well.
BlueGUI works fine for me until I start seperating the code out between functions and source code files. Like, If i have a panel created in one .dba file, then try to add any child gadgets onto it in another .dba file, it doesn't work. Usually that'd work fine, but it doesn't seem to like it now. Treeview gadgets seem to be full of problems for me now as well. Sometimes they work and have huge + signs next to items on them, or they don't appear, or I mouse over them and my program crashes.
I noticed evolved gave up on his Mapscape editor as well because of BlueGUI playing up. All seems to have happened over the last few 7.x updates.
Anyway, I guess by making my own GUI it'll be easier to fix and a lot more flexible.
Very nice terrain editor you have there too by the way.