You can turn off the autohiliting in the button. (Choose the Button tool
and double click on the button. In the dialog that opens up, uncheck the
"hilite" box.) The Human Interface Guidelines state that only one item
(text, a button, etc.) can be hilited at a time.
This article is adapted from the Claris Tech Info database.
alternate search terms: highlight hilite highlighting autohilite
autohightlight hilite