haven't heard any.
I think it's a low-level driver issue; CDex is a Wintendo application based on cdparanoia, and I've had problems ripping non-protected CDs from some pressing plants with it on my NT box at work (either because of two marginal CD-ROM drives in a row or because of the general poxyness of NT's CD handling).
My PowerBook does it just fine; except that (a) it doesn't make .m3u files, and (b) it's hardwired to cddb.org, and I'm not submitting any track listings to those scumbags.
Are there any reports of people successfully ripping copy protected CDs with cdparanoia for Linux? That seems to be able to rip just about anything, including severely scratched CDs, even if it is a bit slow.