Since updating my iPhone 4 to iOS 6.1, it will now not connect to iTunes Match at all.
I had issues with playback immediately after, so I turned Match off and on on the iPhone - now there is no music in the library available at all. I have turned it off and on on my Mac as well to see if that helped, but no difference.
I have done a soft and a hard reset, and also toggled show all music as an option.
Now, when I click on my Music app - there is no music available. The cloud icon shows up on my screen, with the progress bar underneath - but no matter how long I leave it, the bar doesn't progress at all and eventually turns the app off after 10-15 minutes. Then, when I go back in there - iTunes Match has been turned off again.