If you open a conversation and click on emoticon icon so that the stadard panel appears, then click more. You now have the option to remove emoticons from the panel or pin other emoticons to the panel. I don't know how to reset it, but this can let you modify it.
/ 
![[Image: rhcpsig38tj.png]](http://img147.imageshack.us/img147/4060/rhcpsig38tj.png)
