Found it!

[Robert van Herk]

>>Did you also experience that it says "Unable to set configuration key" 
>>for anything you'd try to change?
>>    
>>
>
>Ah, well basically you need to change the header to point to a winecfg
>specific registry branch. The way config in wine works is like this:
>...<SNAP>
>  
>
Okay I'll give it a try.

I was just thinking: from the wine documentation I figured that every 
global setting could be overwritten with an application specific 
setting, right? This is said - kinda informally - in 
http://www.winehq.org/site/docs/wine-user/config-file, in the table in 
the section "What does it contain".

But from what I see in your program, I would say that that wouldn't work 
currently with your lay-out, since Applications is just done on 1 tab 
sheet. Am I missing something? If not, did you do this on purpose, for 
example because you would prefer user friendliness above completeness?

Would it make sence to alter the program in such a way, that first you 
choose for what part you want to change something (either global or a 
specific application) and then, on a second frame/form/window (I don't 
know which word to use in this context), really do the changes, kinda 
like the Network setup works in Win95?

I mean: there you first select the protocol you want to change, and then 
a new window opens in which you do the settings themselves... Would that 
be a good idea?

Grtz,
Robert