I am having problems with the kerning of Postscript fonts from URW (older ones from 1994). These used to work effortlessly in CS3 and before, but now they give the curious problem that the bold weights from a suitcase do not show kerning, where the regular weights show it normally. URW used to issue their fonts (from the typeworks collection) in different forms, the "family" way: as suitcases containing regular, italic, bold, bold italic (when available) or as seperate suitcase for each weight. The kerning works for the single weights, but does not for the family, or at least not for the bold weights.
Do you have any idea why this is the case, does it have to do with CS5.5, or does it have to do with the OS (lion)??