The 2 coins in and under the warehouse are located in a really badass way. The following images i made show how to jump to them.
http://img715.imageshack.us/img715/5536/jumptocoin.gif
http://img829.imageshack.us/img829/646/jumptoillusion.gif
Also, the map to Illlusion at http://www.yolkfolk.com/site/showmap.php?map=53 is incorrect. A correct one can be found at http://members.multimania.co.uk/dizzytheegg/images/maps/illusion3.png
(i can make a replacement image if you don't wanna bother with copyright issues)