So you've gone through the arduous process of backing up and syncing your iPhone, downloading the new software and finally, after what seemed likes hours, getting iOS 4.2 running on your handset.
But what's this? There's no music listed in your iPod app, despite your device's iTunes page saying that it's got 8GB of audio loaded on to it. Damn and blast Apple, why can't anything ever be simple?
Luckily for you Pocket-lint experienced the very same error and, again, luckily for you we did the dirty work searching through the various Apple online forums to get the solution.
And we found a relatively straightforward fix (although not as straightforward as it just bloomin' working as it should Mr Jobs).
Firstly, plug your iPhone back into your computer, then in iTunes open your device's menus and play any song listed under Music. Then sync your music again (you can cancel the backup when it starts).
Et voilà, all sorted.
It doesn't actually sync the music again, as it's already there, it just re-configures it so it doesn't take very long.
We had a similar issue on our iPad as well, but a secondary sync seemed to sort that issue out quick-sharpish.
Have you stumbled across any other iOS 4.2 bugs that we should know about? If so, use the comments below to fill us in.