[SDL + TKD] Seg fault from creating DirectoryDialog

[Jack via Digitalmars-d-learn]

Well, to start, I'm trying to create a mp3 player for 
"educational purposes".
I'm using DerelictSDL(SDL_MIXER) as a library for the backend and 
TKD for the GUI.

I have two objects to represent the two. The constructor for the 
sdl one contains the syntax for loading the DerelictSDL 
modules(DerelictSDL2.load()) and to initialize the SDL library 
(SDL_Init(SDL_INIT_EVERYTHING)), and the constructor for the TKD 
application initializes the sdl object.

// constructor for tkd
this() {
Sdl sdl = new Sdl();
}

//constructor for sdl
this(){
DerelictSDL2.load();
/*etc...*/
//

and I set a command function to a button that creates the 
DirectoryDialog.

at least, that's what it was supposed to do.

Whole error is: http://codepad.org/C2l4rUel

and gdb spews out a segmentation fault error:
http://codepad.org/X6CqH3vK
That, I think, revealed a threading conflict between the two 
libraries.

Can anybody with enough knowledge point me to the right 
direction? or just confirm what I have?