Q: When I connect my iPod via USB to my computer, it takes a long time to appear on the iTunes page. When it does, a window pops up telling me that it has detected an iPod which is corrupt. If I then unplug and retry, I can eventually get a connection that works. What would be the reason for this “corrupt iPod” window, when the device is in reality just fine?
A: The first thing that is important to understand about how your iPod interacts with your computer is that it’s really just an external hard drive or flash memory device as far as your operating system or even iTunes itself is concerned. There’s really no “magic” interface between iTunes and the iPod—rather iTunes just writes to the iPod as an external storage device, updating files and databases directly through the file system.
What this means in practical terms is that many other tools and utilities that may be running on your computer will also see the iPod as just another external hard drive that is showing up on your computer. If you look in Windows Explorer or Finder (Mac) when connecting your iPod, you will actually see it appear as a drive while iTunes is accessing it. If you are using automatic synchronization, it will normally automatically eject when the synchronization has completed, unless you have specifically enabled “Disk Use” for it in iTunes.
If the iPod is in fact working fine, and you are not having any problems with music playback on the device or synchronizing it to iTunes, but still receiving messages regarding a corrupt iPod being detected, the most likely cause is some other system management tool, anti-spyware tool, or anti-virus utility on your computer that may be detecting the connected iPod as a hard drive that it should be scanning or performing some other type of maintenance on. This can get in the way of what iTunes is trying to do with the iPod, since a virus-scanner may lock files on the iPod that iTunes needs to access, with the result being that iTunes produces an error message.
The simplest solution to this is to look at the drive letter that the iPod gets assigned when you connect it to your computer, and then go into any anti-virus tools or system management tools that you may installed, and exclude that drive letter from being scanned. This will prevent any other program that may be running on your computer from trying to access your iPod while iTunes expects to be updating it.