iPhone has deleted all my music?

I have the same problem...
And now my iTunes has a serious problem which i can't fix.
So, I can't put music back on grrr.
HELP US!

I have the same problem. Just happened today after I purchased an album from iTunes. It finished downloading, the phone locked up, I rebooted, went into iPod app and only my recent 2 purchases were there.

My capacity reading implies that the music is still there, but it's just not showing up.

WTH?

Just chiming in to say that I have the same issue on my iPod Touch since I installed OS 3.0. If I download a podcast directly onto the iPod over WiFi (rather than getting the podcast onto the iPod by syncing it with iTunes) the next time I go to listen to music I get the "Updating Library" notice after which the only music available is that which I have just downloaded.
I know for a fact that this did not happen with OS2. This is really annoying while travelling. If anyone has a link to a fix, please post it here.

I'm on a Mac and have that same problem I posted a topic. "my itunes is not accurate".

Hi rugratmike. No offense, but that topic you posted is not about this issue at all.

It happens after downloading a podcast over WiFi. Ipod gets real busy for a minute, then all songs, videos and about half the other podcasts are just gone. Got to resynch to fix. This can't be intentional behavior. Stared with release 3.1.2. One clue this happened of one of those sign on required public wi-fi's that times out every 15 minutes or so, but it didn't time out.

I just had the same problem with 3.1.2 but on both my iphone 3gs and ipod touch 2nd gen. both are doing exact same thing.

FOUND A SOLUTION. EVEN THOUGH MY IPOD AND IPHONE GS SHOWED NO VIDEOS OR MUSIC, WHEN I CONNECTED IT TO ITUNES, ITUNES SAID THEY WERE ALL THERE. BUT i STILL COULDN'T ACCESS THEM, SO I ADDED ONE SONG TO BOTH AND WHEN BOTH UPDATED THEIR LIBRARIES, BOOM, ALL THE VIDEOS AND MUSIC CAME BACK COMPLETELY! SOUNDS LIKE A BUG OF SOME SORT TO ME. HOPE THIS HELPS

revdr, I really can't tell if you're trying to make fun of the people with this problem. Typing in capitals and saying "SOUNDS LIKE A BUG OF SOME SORT TO ME" really doesn't give the impression of seriousness. It's not really a solution if you have to go back to your computer to re-sync your iPhone. The point is that the content becomes unavailable while you're on the road (according to the above posts it is often just after purchasing some music over WiFi).

Maybe a simple description of the problem would be useful here for people claiming to have solved it:
1. There is music (and videos) on the iPhone/iPod
2. (This part is not reported by everyone) You download a new song / podcast directly from the device over WiFi.
3. Next time you use your device, there is no content on it at all (or ONLY the song(s) you just downloaded).
4. The iPod / iPhone reports the correct amount of disk space is being used.
5. Next time you sync the device with your computer, everything is back to normal.
6. This whole thing happens every time you download a song over WiFi.

Is this what everyone is seeing? I have a couple of questions to see if we can help to diagnose this better. If you add to this discussion, please answer these:
1. Which version of iTunes are you using? (iTunes 9 gives me a 30-second beachball every few minutes - separate issue or related?)
2. Are you in the same country that your iTunes account is registered? (I recently moved and I thought maybe my iTunes store login info was somehow tied to the Finnish store but now that I'm in The Netherlands there's some DRM conflict.)

This happened to me today after I downloaded iTunes U podcasts over wifi. All music/videos are still shown in iTunes when the iPhone is plugged in, and I can even take songs off the iPhone using 3rd party software (which is installed on a work PC). I can't sync with my normal iTunes as I'm at work but I can use the other software to put songs back on the iPhone, which doubles them up when viewing the iPhone content back in iTunes.

This is the first time I have downloaded anything over wifi since upgrading to 3.1.2, and there was no problem doing exactly the same thing on 3.0.1

This happened to me tonight, but I was downloading a podcast on a 3g network. I have itunes 9 and a iphone 3g running 3.1.2 While d/l'ing podcast answered an incoming call, after call all music and video and podcasts are gone. In general->about says 0 songs 0 video but my available memory is only 2 gb as if all the music etc was still there! After syncing iphone is complete I go to ipod app while iphone is still pluged in and it says to wait for library, then it all comes back, did not have to add another song as previously suggested.

This has happened to me today as well. I bought an album over the wifi connection from my iPhone 3G and synced it the next day using the latest version of iTunes. I did not click "Transfer Purchases from iPhone" but this has never caused any problems before.

Then this morning I discovered that the only items that would appear in the iPod application were from the album that I had downloaded. As other posters have stated, the "About" tab in the settings menu still shows the memory full of songs.

I have not yet been able to get to my computer with iTunes to try and sync the phone to solve this problem. I do hope there is a solution forthcoming.
Thank you for reading!

iPhone 3G with O2 3.1.2
Sync'd with a computer running Windows Vista.

Just posting an update to my previous comment. Today I managed to plug my iPhone into my computer with iTunes running. Immediately my songs returned withot my having to click anything.

While I'm glad that this seems to have solved the issue for now, it is obviously not an ideal state of affairs.

I had the same problem today: I downloaded two songs over the 3g network and bam, all 1200 of my songs were gone EXCEPT for the 3 I had purchased over the network recently, but not one I had purchased over the network about a month ago.

I have a 3G with the most recent software update...I think 3.1.2?
The computer I'm currently using doesn't have my iTunes library on it, but when I hooked up my iPhone to my laptop with iTunes running (but no music in it), my music magically reappeared....hmm.