Haven't bothered to test the script, but I'll make a few quick guesses just from looking at the script.
First off: Is it an issue to set
ALWAYS_ON_TOP to false?
If so, then put it to false and do this. Find this line
@icon_sprite = ALWAYS_ON_TOP ? Sprite.new(topview) : Sprite.new(viewport)
And right below it put this:
I think that should work...my mind has been filled with code for the past 3 days. It's getting hard to focus on 5 projects at once.