Icon id conflicts?

[David Epstein]

I am moving a project I created in LC 5.5 to LC 10.0rc1.  Some buttons have their icon set to the id of an image found in a stack “in use.”  In some cases, this still works, but several buttons no longer look right in LC10, I assume because the icon number exists somewhere else in LC10.  How can I go about finding and imposing an id number for my image that will not encounter this conflict?

Alternatively, the dictionary says I can use an image name as a button’s icon, but the LC property inspector doesn’t let me enter non-numbers as an icon, and setting the icon to an image name from the message box has no effect (the image named is in a stack “in use”).

David Epstein