I found this rather easy.
Pardon the stretching; I'm running it with some odd version of wine with problems. Also, I didn't spawn any items at all or do things outside of the screen capture and I'm not sure if those even would have helped.
Disposal of useless thing:
(http://img808.imageshack.us/img808/9806/nc00.png)
In position (do this correctly if you like it easy):
(http://img812.imageshack.us/img812/6529/nc01.png)
If you did that correctly, you should be able to land on the bird fairly easily:
(http://img819.imageshack.us/img819/4555/n02.png)
Victory:
(http://img821.imageshack.us/img821/5804/n03.png)
And the key is up there with the door so just go back up there and leave
Okay I got the 1.0 version and I was still able to do it similarly but it was a much closer call (landing on the bird right as it's stepping off and barely making it to the coin).
(http://img684.imageshack.us/img684/7877/201006111234011680x1050.png) or something like that; it all went by so fast
To do it with the blue jumper you just put it over the gap and fly under it with the bird. When it jumps, you will go up, and when it falls back down it'll slam you down low enough to get to the coind and back ;)