So, are you using an ImageList here, or what? I wouldnt recommend using .ico files for things like toolbars and whatnot, since they can act a bit wierd (showing the wrong size at times or whatever). I suggest you extract the files you need and save them as bitmaps (icons are basically just a bunch of little bitmaps in one file, anyway) and use those.
Sorry if I misunderstood your problem - you were a little vague.