Updated to 10.6.3 and Gill Sans Ital died a horrible death, and the character spacing on Gill Sans Regular all messed up as well. Specifically, in Keynote '09. A presentation that I delivered just before upgrading to 10.6.3 ran beautifully, since, the font - Gill Sans, for all it's flaws, is the default - changed dramatically, busting text boxes and in the case of using ital, garbled completely.
Both of these presented perfectly on the 10.6.2 MBP, but when I opened them again after upgrading to 10.6.3, this is what I get, notice the overrun on the text box and the complete garbling of the Gill Sans ITAL.


Both of these presented perfectly on the 10.6.2 MBP, but when I opened them again after upgrading to 10.6.3, this is what I get, notice the overrun on the text box and the complete garbling of the Gill Sans ITAL.