A little while back I had an issue when trying to sync my iPhone with my mac. Any calendar entries made inside iCal would sync across fine to the iPhone, but when done the other way the new entries wouldn’t appear in iCal.

I went through various solutions last time and the only way to make it work again was to reset the iPhone and re-sync everything. This morning I had the exact same problem and didn’t particularly fancy having to reset my phone again and go through the rigours of setting it up how I liked it again.

I came across many posts detailing different fixes but none of them seemed to work for me. I tried resetting the sync history using the button in iSync preferences, but a restart later and I still had the problem. Looking at the Apple support document for resetting the SyncServices folder showed another way to reset the information. Open terminal, copy and paste and then hit enter:

/System/Library/Frameworks/SyncServices.framework/Versions/A/Resources/resetsync.pl full

When re-opening iTunes and the iPhone plugged in you’ll initially see no calendars, no email accounts and no address book groups. Select the options you want to sync again then click sync and that information should re-appear.

I have no idea why the calendars stopped syncing correctly, but I did notice that some old calendars that have been deleted still showed under the sync list. They weren’t being synced, but could have been a contributor to the problems I’ve had.