It seems that in the version 6.07.01 I am unable to put more types of coin into a coin bag. I am not sure if this is intended behavior or not. However, when I add additional coin bags to the inventory I am not able to put coins in any of the other coin bags either.
It seems there is some element of variance involved. When I created a new character I was able to put multiple types of coins in a purse. It might have relation to using a different source (3.5 core rules I-III instead of the 3.5 player) I am going to try and figure out how to reproduce this more accurately.
I found the item in the datafile was limited to a number of items.