// in ToolButton.cpp:

void  ToolButton::Paint(Draw& w)
{
    ...
  
    int li = IsEnabled() ? HasMouse() ? GetMouseLeft() ? CTRL_PRESSED
		                               : checked ? CTRL_HOTCHECKED : CTRL_HOT
	                       : checked ? CTRL_CHECKED : CTRL_NORMAL
					     : CTRL_DISABLED;
   ...


// in Win32Proc.cpp, around line 71:

// returning false here was enough to cease all crashes!!
bool GetMouseLeft()   { return false; } //!!(GetKeyState(VK_LBUTTON) & 0x8000); }