icon id, x y w h, filename, index, style (noborder top left bottom right)
icon , 1, 50 50 100 100, "blabla.bmp", 1, noborder
what is the actual width and height of the bitmap
you have after the file name" 1," ("blabla.bmp", 1, noborder) yet in the example right amove from the help file it shows Either use Index which will go in the frame replacing the mIRC icon at the top left of your dialog, or use the "styles" of (noborder top left bottom right). Not both, not 1.
one thing I have seen in using images in dialogs as you may need to use negative number to properly register the icon. Whether or not this is while using DBU or not I am unsure as I always use DBU as the dialog type option.
so icon, 123, -10 -25 70 100, noborder
when using an image as the icon for the index, 16 x 16 to 64 x 64 is about it for definition.