The iPad may be slow to start syncing (after the “Apply” button is pressed) or cancel syncing (by sliding to cancel on the device itself). Syncing itself can also take an inordinately long time relative to the data being transferred.
As described by Apple Discussions poster Randy Bisig:
“When I plug in the iPad or start a sync by clicking the button on iTunes, iTunes will lock for 45-75 seconds before Sync in Progress appears. And when I mean ‘lock,’ even music stops. If I move icons around then click on Apply, the sync will not start for nearly 2 minutes. Then, music stops until the sync is complete.”
- Reinstall iTunes. In some cases this issue can be resolved by completely removing then reinstalling iTunes as described in this Apple Knowledge Base article.
- Remove third-party backup software. If you’ve installed software for an external hard drive or another device, it may include an automatic backup utility that recognizes the iPad as a storage device, interfering with the normal sync process. Try uninstalling any such software then re-syncing your iPad.
- Remove iToner. It appears that the presence of Ambrosia Software’ iToner software may cause problems with syncing the iPad. Navigate to ~/Library/iTunes/iTunes Plug-ins and /Library/iTunes/iTunes Plug-ins (the Library folders inside your user folder and at the root level of your startup drive) and look for a file called iTonerSupport.bundle. Remove it, then restart, and check to see if iPad syncing occurs more quickly.