Firstly, are you using Windows or a Mac? Do you know if you have your iPod in "disk mode" or "manual synchronization" (if you don't know what those are, then the answer is probably no).
I would suggest closing iTunes completely, and then attempting to eject your iPod through the system tray (Windows) or Finder (Mac) and see if that helps.
Also make sure that you don't have it highlighted in Finder (Mac) or have the drive letter for it open in Windows Explorer or My Computer (Windows).
Worst-case scenario, a reboot of your computer should also release it (I realize that you don't want to have to reboot every time you want to disconnect your iPod, but it's also possible this is a one-time problem).
If it is something that is happening consistently, you may want to look at what other applications that you have running that may be interfering with it. When the iPod is being synchronized with iTunes, it is connected as an external hard drive, so there are a number of utilities that might be accessing it behind your back.
Its on Windows, no disk mode & no other applications open,
this is a 4th gen, I upgraded from a 3rd which worked perfect.
From new i've had connections problems either won't connect or won't eject. I've stripped out all the software re-installed, usually as you say I have to re-boot or reset the ipod....
The only other likely cause that I can think of might be a problem on the iPod itself, especially if this is happening consistently since you upgraded.
Although time consuming, it may be worth doing a complete Restore of your iPod, using the iPod Updater. This will basically reformat the iPod, so you'll want to make sure that your music is in iTunes (or that you at least have a backup of it all somewhere).
You'll also want to check at the same time that you're using the most current iPod firmware. If your firmware is old, try updating that to the current version first (the iPod Updater will do both of these things for you).
Hi tried that,,,,you can't reset the ipod and reload the software as its unable to lock the ipod.........doing a search it seems a number of people are having the same problem....... most are just unplugging the ipod when the sync is complete..
I just got a brand new 60gb on Thursday upgrading from a 3gen 15 gb. Zero problems until today when I got the same problem as the other fellow on this board. After heavily updating all cd art on all songs, I synced up my iPod to make these changes. At first, I noticed itunes was freezing up really bad in the beginning, but then caught up. When then attempting to eject the iPod, I got the same message stating that it could not eject as there were files being used by other programs. Closing itunes and all corresponding apps, I then attempted to safely remove hardware from the taskbar to no avail. It simply stated that the hardware could not be stopped and to try again later. Sadly, I had to disconnect with it still running not once, but twice as I attempted to restart my computer to see if it would work. It did not.
To solve for this problem, I did two things, I'm not sure which one worked. One, I disabled synching of photos to the iPod. I did not have the problem until I began synching photos, so this may be the issue. Two, I resintalled the firmware update to my computer disk drive, but it did not update the firmware on the iPod. Since the firmware was not updated on the iPod, I have to believe the recent release of iTunes has an issue with synching photos. Turning it off seemed to fix the problem for now, but I'm hoping that it will remedy itself in the future. Hopefully this helps.
I don't know if it is a definite method, but whenever I get one of those messages, I would go to My Computer (windows), right-click on the drive letter and click on 'eject'. This has so far worked for me whenever the system tray and itunes both won't disconnect my iPod.