Well I just read through the first 8 pages of this thread and figured I'd give my experience with this mismatching.
Extra info: I'm on the newest version of OSX 10.7.2, iTunes 10.5.3, iOS 5.0.1 (iPhone 4S)
I've had iTunes match since day one, but already had alot of music synced to my iphone with usb and itunes. When you enable itunes match on the iphone for the first time it states it wipes all your music but I'm pretty sure it didn't. I was only adding a few songs here and there with itunes match and slowly started noticing that some songs that weren't on the iphone before itunes match were downloading edited.
At first I was having problems with music no matter what the original source was. I was having other problems with my iPhone (random shutting on and off) so I wiped my iPhone a few days ago, restored and just started putting music on again via itunes match only. This is when I noticed alot of music is now edited on my iphone that wasn't edited before the restore. This is what leads me to believe that previously synced music wasn't actually wiped from the phone even though itunes match said it would be. I think it just states that becuase when the phone starts running out of HD space it will delete music to make room for new music. Hopefully you're not confused yet!!!
Today I was on the phone with an apple rep and they told me to go on my iPhone go to the settings > general > restrictions (they were disabled, I had to enable them and set a passcode) > Music & Podcast > explicit (explicit was already on, but if it's off turn it on). Then go on my computer, open iTunes Preferences > Parental > Uncheck Restrict explicit content (it was already not checked). I think this might have solved iTunes purchased music to now be downloaded in explicit. I went through some of my music and it seems for the most part that anything I bought through iTunes and has the red explicit tag next to the song title is matched correctly. So when I download these to my iphone they are still explicit. I've done it with 2-4 tracks per album, with different artists, and different genres (hip-hop and rock). They all seem to be correct now even though a week ago when I downloaded them some were edited. To be specific, I downloaded some tracks from Kanye West & Jay Z Watch The Throne and they were edited prior to this, before the restore.
Only 1 cd I bought/downloaded from Amazon has explicit lyrics in it and this now downloads to my iphone correctly now. It didn't previously. A track from this cd was originally one of the songs I noticed previously downloaded edited. In itunes the cd doesn't show the red explicit label next to the song title but it says "[Explicit]" after each song title as well as after the albumn title. The iTunes info states these are 256 kbps mp3s, ID3 Tag: v2.3, Encoded with: Lame.
Now for the fun stuff! I have two full albums I got from "other places," but are said to be ripped from original CDs. They are both 320 kbps mp3s. One cd is Drake - Take Care and the other is Game R.E.D. Neither of these say Explicit anywhere in the info. The album artwork does show the explicit cover... probably doesn't matter but I figured I'd add that anyway. On both albums, none of the original mp3s are edited on my computer. I just listen through both of the cds to be positive. Some tracks are uploaded and some are matched on each album. I downloaded both cds via iTunes match to my iphone today. One cd has 20 tracks the other has 21. Only 4-5 tracks on each cd downloaded Not edited. Some of these not edited songs were matched some were uploaded. As for the rest of the tracks, it DOES NOT matter if they show matched or uploaded to icloud on my computer, they all downloaded to my iPhone from the cloud Edited. I actually have the list of whats uploaded and matched and what downloaded edited/not edited if anybody is curious about that. This post is already pretty long so I didn't want to add that to it.
As for CDs that I have personally ripped to my computer, I couldn't find any that added the explicit label to them in the info, I know some people asked about that in this thread. I've used all different programs to rip them including itunes. Some were ripped 10 years ago and some as recently as a couple months ago. Most are from a couple years ago or more though. Maybe I'll try to pull a couple cds out and re-rip them and see what happens. I've probably ripped 100 or so cds myself. Alot were also ripped from previous roommates from CDs and some are ripped from vinyl. Had a roommate with some turn tables not sure what he used to rip/record them. Some of these are matched, some are uploaded. Some tracks on each album are matched while others are uploaded. I think this is pretty much the same as everyone else's experience. As for these tracks, it also DOES NOT matter if it's uploaded or matched. Some tracks download edited and some do not.
Is anyone else seeing tracks that are stated as uploaded to the cloud, downloading edited?
I'm not sure why they don't just make an option to download either edited or non edited and let you be able to change it in iTunes match settings. I have clean and explicit music because my girlfriend teaches dance and needs clean music. I find it ridiculous that we have to pay for both explicit and clean music anyways, when she needs to use clean and I already purchased the explicit version. I understand paying if its a remix of the song but it's usually not. Anyways this would at least be a short term solution!!