Debugging things in VS it seems the problem lies in fltk.lib in the gdi driver code:
fluid.exe!operator delete(void * block) Line 38 C++
fluid.exe!operator delete[](void * block) Line 32 C++
> fluid.exe!Fl_GDI_Graphics_Driver::create_bitmask(int w, int h, const unsigned char * data) Line 393 C++
fluid.exe!Fl_GDI_Graphics_Driver::cache(Fl_Pixmap * img) Line 806 C++
fluid.exe!Fl_Graphics_Driver::draw_pixmap(Fl_Pixmap * pxm, int XP, int YP, int WP, int HP, int cx, int cy) Line 242 C++
fluid.exe!Fl_Pixmap::draw(int XP, int YP, int WP, int HP, int cx, int cy) Line 48 C++
fluid.exe!Fl_Image::draw(int X, int Y) Line 295 C++
fluid.exe!Fl_Tree_Item::draw(int X, int & Y, int W, Fl_Tree_Item * itemfocus, int & tree_item_xmax, int lastchild, int render) Line 1104 C++
fluid.exe!Fl_Tree::draw() Line 733 C++
fluid.exe!Fl_Group::draw_child(Fl_Widget & widget) Line 961 C++
fluid.exe!Fl_Group::draw_children() Line 917 C++
fluid.exe!Fl_Group::draw() Line 932 C++
fluid.exe!Fl_Group::draw_child(Fl_Widget & widget) Line 961 C++
fluid.exe!Fl_Group::draw_children() Line 917 C++
fluid.exe!Fl_Window::draw() Line 523 C++
fluid.exe!Overlay_Window::draw() Line 344 C++
fluid.exe!Fl_Window_Driver::draw() Line 82 C++
fluid.exe!Fl_WinAPI_Window_Driver::flush_overlay() Line 349 C++
fluid.exe!Fl_Overlay_Window::flush() Line 53 C++
fluid.exe!Fl_Window_Driver::flush() Line 204 C++
fluid.exe!Fl::flush() Line 755 C++
fluid.exe!Fl_WinAPI_System_Driver::wait(double time_to_wait) Line 521 C++
fluid.exe!Fl::wait(double time_to_wait) Line 581 C++
fluid.exe!Fl::run() Line 600 C++
fluid.exe!main(int argc, char * * argv) Line 2023 C++
fluid.exe!WinMain(HINSTANCE__ * hInstance, HINSTANCE__ * hPrevInstance, char * lpCmdLine, int nCmdShow) Line 113 C