OK, Hat, I think I've found your problem. The internal name for all the coins is identical, when it should be unique for each of them (i.e. each new object with its own GUID must have its own internal name). So, when the game loads up, the coins are all referring to the same object, hence they all have the same texture (and probably also the same game-play properties, although I didn't test that). (Is this making sense?!)

Now the bad news: I tried to fix it, but got a weird error in SimPE, which just made everything worse. So, unfortunately, I think you are going to have to remake them from scratch!

When you clone the original object, you need to make sure that you enter a unique name for each of your coins in the Scenegraph Rename Wizard dialogue that pops up.

I use this tutorial here on object creation: http://www.modthesims.info/showthread.php?t=104795. Obviously, just ignore the stuff about Milkshape and UV mapping, and follow the instructions on what to do in SimPE when creating a new object, and hopefully it should work!

EDIT: oh, and it looks as though the original object was cloned from a base-game mesh, so I think they are already base-game compatible. :)