I have the same disconnection problem when it tried to backup.
It finally worked when I deleted the large cache files in one of the apps (Fltplan), which contain a huge GPS map for offline use.
So if you have any app that stored some hugh cache files, delete them from your iPad.
I had tried many of other suggestions, and none of them worked. This included:
- hard-resetting the iPad (by pressing both sleep and home buttons simultaneously)
- resetting the the iPad settings to factory-settings
- re-installing iTunes
- deleting old iPad backup from ../Library/Application Support/MobileSyc/Backup
None of them worked, except when I deleted the cache files of the app that takes up huge space, it worked instantly.
So look for any app that you think it stored huge amount of data in the cache, and delete those caches.
Hope this helps.
I have the same problem, which started after I upgraded to iTunes 10 and version 4.3.5 for the iPad and have tried every solution offered on this and many other forums, but without any luck. The fact that so many users have backup and or sync problems, seem to indicate that there is a big problem with Apple's software. It is time Apple starts doing something about this. I was about to buy an iPhone, but will not do so because I am worried that I will have the same problems.
I think the problem lies in not having enough disk space in your iPad. It needs some fair amount of temporary disk space to complete the backup process. When it ran out of space, it just crashes.
The app that was causing my problem was FltPlan, which I had downloaded the maps of the flight plan in the cache (temporary storage). (When you download the entire map of the United States, it eats up a lot of disk space.) After I deleted the downloaded maps in the cache of FltPlan, iTunes backed it up without a glitch.
So the solution is: make some room in you iPad. Delete the temporary cache (if you are techie enough to do that). If not, just delete some apps. Don't worry, you won't lose them, because you can always reinstall the same deleted apps later from AppStore (because Apple has a record of all your purchased apps in iTunes/AppStore, and you can always reinstall them in any device you have - either iPad or iPhone or your Mac. You can easily find all your apps that were "purchased" but "not on this iPad" button in AppStore/iTunes and reinstall them later after you completed your backup).
If you delete the app first before backing it up, delete those apps that you don't have any saved document or saved settings, such as if it is an text editor and you have written notes in it, don't delete it, otherwise you will lose your notes. Same for games, if you have played the game and saved the level your are in, when you delete it, you will lose your scores. So delete those apps that you don't have any save data in it.
After you made some room in your iPad, then backup with iTunes.
I think Apple should give a warning telling you that it ran out of disk space to complete the backup. That will save some grief for everyone.
I've been having this problem for a while. I've reset my iPad. I've made room on my iPad. I've deleted the backups. I've reinstalled iTunes. I've stood on one leg with my arms over my head while I said the pledge of allegiance. Nothing seemed to solve the mystery of the backups not working. But what finally worked was this: Use a different USB port. Try either a legacy USB port or a USB 2.0 port. Do not use a USB 3.0 port. My iPad just completed it's first full back up in 6 months because I was using the wrong port.
Good luck and hopefully this works for you too!