Are your fonts applied through paragraph and character styles? If so, you'd best replace the fonts by changing those styles.
actually, just figured it out!
fonts needed to be removed and re added via font book.
all is well...so far
This happens on all the machines?
yeah i tried that too. no dice.
Currently it's a Mac only issue.
After disabling the fonts in Suitcase and and activating them in Font Book i have been able to replace some of the intances via the "Find Font" function but for the most part it still wont allow the substitution via "Find Font"
Are you using the latest version of Suitcase? What happens if you remove the autoactivation plugin?