All of a sudden Quark (7) has stopped accepting psd imports, when it had been working fine for well over a year. I haven't intentionally changed any workflow either in Quark or in Photoshop. Photoshop files are being saved with previews, but for some reason now almost every time I import a psd with even the simplest layers -- no layer effects, alpha channels, curves, masking or anything complex -- I get a message that it has effects that Quark can't import, and displays it with the multi-language text blurbs claiming (falsely) that the file has no preview.
What's going on? Is this a Quark problem or a Photoshop problem? How might I make it work again? Would throwing away my preferences for one or the other application be likely to help, or just a waste of effort recreating all my preferences from scratch?