No, I don't think it's a plug-in either, but I can't otherwise explain why a certain feature would be unavailable. I do all my PS work in 8 bit, now and before. I've tried different files, including ones I've Saved to Web with before, same problem. I'm considering a reinstall, but hope to find a solution short of that.
I just noticed something else - the Filters menu is way abbreviated, not nearly as full of options as the CS2 I have on my Mac Pro. None of the Extract, Filter Gallery, etc., and only a handful of the filter classes below that. Something ain't right...
I've posted this on the COW Photoshop forum, not much response yet. I appreciate any bright ideas.
Scott