Having the same problem here on an iMac. Everything worked fine in Lion, and since Mountain Lion match has failed to work. I wouldn't really mind, but every time match restarts (about every 60 seconds) iTunes focuses on the iTunes Match window no matter what I am doing. It will even maximize iTunes and focus it to do this. When I am working on the mac (rarely, but sometimes I have to) it is extremely annoying - what happened to 'quietly and in the background'???
I have followed all the steps here and it still persists.
Out of my library of 15,230 tracks...
12,344 (81%) - have an 'error occured' message.
432 (2%) - were ineligible
2449 (16%) - were successfully moved to the cloud
Obviously these were done before mountain lion. I guess it is hardly worth me having this service anyway?
Right now there is nothing moving back and forth at Apple. The match process stalls sending results to Apple. iTunes aborts with the message of a network problem. Please Steve, step up from the grave and hold another townhall meeting. This one definitley has the taste of the MobileMe Launch years ago. The ongoing issues with iTunes Match really is tarnishing Apple's reputation.
Mid 2012 MacBook Air, same problem as orignator, network failure when sending to Match information to Apple. Updated my network DNS to Google (126.96.36.199 (pri) 188.8.131.52 (sec)) on my Airport router. Signed out of iTunes. Downloaded and re-installed latest version of iTunes (www.itunes.com). After re-install opened up iTunes, signed in, selected Store -> Turn On iTunes Match, worked like a champ. Everything is synced on all my devices!
Did the same - no effect. I even tethered with my iPhone using the cell connection. No change in iTunes behaviour. Conclusion: the problem is not on users end. See also https://discussions.apple.com/thread/4256049?tstart=0
I'm having the same issues here - Based in the UK.
Installed Mountain Lion a few nights ago and kept noticing weird iTunes error messages. Then noticed it wasn't uploading any of my new content.
The messages are becomming so annoying that I may have to turn off match altogether. If Spotify didn't do all it's annoying matching with your local files I would probably discontinue iTunes altogether as my patience with it is wearing more than a little thin.
The problem that occured yesterday seemt o be fixed.
The second one that lasts since Mountain Lion came out at still persists. Every 60sec rescan of iTunes Match. That fact prevents iTunes Match do run through entirely.
Once again I was testing tethering my iMac to my iPhone and see if the match process still got's interrupted.
I did two attempts with htaht setup and it worked out. 4 new songs could being matched, 2 uploaded successfully.
It then crossed my mind, that I have slow response times with my cable network, since two weeks now. That coincides with the release of Mountain Lion. Yes, exciting.
May I ask what internet connection you have? Mine is cable, 12Mbit down, 0.5up.
Since Monday evening iTunes Match works flawless.
I was able to add 25 songs to my library in batches of 10, 10 and 5. Each time it works fast (2mins max.) without any breaks just perfect. I did not change anything on my system. That reduces error source down to two:
1. My ISP has fixed something. I however did not recognize any significant improovemtn of my cable connection. In other words I don't there has been any change made here.
2. Apple fixed something.
Let's hope it'll last...
You can see that I had another thread going about this same problem so I will post my fix here:
UPDATE - 20 minutes at the Genius Bar and it was resolved. The tech that helped me out had never seen anything like it before but he and another tech starting looking up stuff on one of the iPads that they have which provides them with solutions to all kinds of problems. He tried a few things on my Mac and then kept switching pages on his iPad for solutions. I'm guessing it said "try this and if that doesn't work then go to the next step". Eventually he got it to work so obviously there is a "fix" out there for issues related to iMatch, iCloud, and the Moutain Lion update.
I asked him what all he did to fix it but he said it was too complicated to explain even though it was very simple. Oh well, rest assured that it can be corrected and hopefully someone will be able to post the fix on here so as to save people trips to an Apple Store. One last thing, nothing had to be removed or reloaded in my iTunes account. I hope this helps you out some.
After a few more days I can narrow down the even further problem. It seems that iTunes Match is a bit too sensitive for slow response times on the network. Each time I add new songs to my library Match is doing its job nicely regardless of my internet connection. That only work smoothly if no songs need to be uploaded. As soon songs could not be matched and uploads are required the procedure breaks up after a few seconds. The whole match procedure then starts all over again. It recently takes a whole night just to upload 6 songs to the cloud. Doing this with my Mac is tethered to my iPhone using a 3G connection it works mostly good.
I tested this around 15 times over the last few days. The behaviour can be reproduced very well.
I guess that depends - in reading these threads about this problem it seems lots of people have called Apple Care or asked on this forum for help about this issue. To date the responses were that there was no know "fix" so I decided to just take my phone to the Genius Bar to see what help that they might provide.
The fact of the matter is that the tech was able to access some directions from Apple that addressed this issue that got my problem resolved or "fixed". So, I would suggest that the next time someone is speaking to an Apple Care tech and they say that they can't fix it I would remind them that it was successfully done at a Genius Bar and for them to keep working on it.
If that doesn't work then the "fix" might be for someone to go the their local Genius Bar until the information is disseminated to this community. It was not a perfect "fix" (I would have preferred to go onto this forum and find the answer instead of having to drive to an Apple Store) but at least it took care of my problem. Remember, I'm just the messenger and my only desire was that my experience might be helpful to others. Have a good day,