[Cross-posted with the UAFDKOML group]
I'm starting to receive some questions about features not working in InDesign CS5 when a non-Latin language or "No Language" is selected. And this is happening with fonts that worked fine in CS3 and CS4.
From the cases I've seen, the bugs were in the fonts. More specifically, the feature file code lacked languagesystem declarations. Regarding InDesign CS5, what I can tell you is that this version is more strict than CS3 and CS4 were in terms of dealing with language and script tags. So if the fonts don't have lookups for all the necessary languagesystems, ID CS5 will just stick to what's in the font rather than creating them on-the-fly, like CS3 and CS4 used to do.