It's now been a year and a half since the original post, and my library is still full of a bunch of 'cleaned' tracks. I'm not going to go through my library & find each track, then find the original CD & re-rip it (I got rid of most of my CDs a few years ago), in the hopes that Apple has fixed that particular track/album. It's especially annyoing when I'm playing music at a party & realize it's a censored version of a song. Have you ever heard a clean version of Nuthin But a G Thang? It's not pretty.
I think this gets at a bigger problem with digital tracks. Right now on the iTunes top Hop-Hop/Rap tracks, Thrift Shop is listed twice - once at #3 for the explicit version, and again at #5 for the clean version. I can only assume if counted together, that track would be #1. Shouldn't they be counting it as one songs, with 2 different versions, rather than 2 completely separate songs? It would be nice to be able to just toggle a switch from explicit to clean. Behind the scenes, iTunes should be able to track the 2 different files but only show one in the interface. This would fix the iTunes Match problem, too. Of course I'm sure the record labels would want to get paid separately for each version, but I'm sure Apple could argue that only x% of people buy both versions, so it really doesn't matter.
Billions of dollars in R&D, yet bugs like this remain. I already submitted feedback twice. Come on, Apple, this kind of stuff just has to work.