Just recently, I have several issues that appear to be related: My iPhone 3GS doesn't complete a sync, my MacBook seems to be running way too hard and the Activity Monitor shows iCalSyncServices and Mingler are the hogs, iCal sometimes does not open, or takes forever to. Sometimes I get this error when trying to sync the iPhone "iTunes could not sync calendars to the iPhone because the snyc server failed to snyc the iPhone". It doesn't get past "step 3" while syncing.
I am on a MacBook, 10.7.3, I only use Entourage (12.3.2) for my email, contacts and calendar and I do not subscribe to MobileMe. The only thing I snyc with is the iPhone, no other outside calendars. This has worked perfectly for years (aside from some duplication issues on the calendars that I lived with) until just recently and I don't know what has changed. I admit I have tried changing a few settings after reading the help forums but nothing has worked, and now I'm not even sure what settings were correct before.
I just turned off the permission for Entourage to sync with anything and Mingler is still running and growing. I've looked for ways to reinstall iCal but from my install disk it is not an option, telling me a newer version is already installed. I cannot even find a folder called SyncServices. My MacBook was purchased early 2008.
Is this an iCal issue, an Entourage issue or a Lion issue? I'm out of ideas.
I found this was due to some events having dozens of alerts, which iCloud or Calendar happily added for me. I solved this by:
1) Go to http://support.apple.com/kb/TS1627?viewlocale=en_US&locale=en_US and follow the instructions for your platform to reset the SyncServices folder.
In my case, it was a terminal command:
I am not 100% sure this was required. But I did it, so I am simply telling you what worked for me. You don't lose any events or any data.
2) Open Calendar and go to Preferences -> Calendar -> Alerts and make sure all the defaults are set to "None."
This prevented syncing from adding alert after alert to my Google and iCloud events.
Take a look at some of your events in Calendar or BusyCal or whatever, and see if you have the duplicated alert issue on some. You may have to delete some old events.
3) Sync everything, and you should go good.
4) Go to iTunes, and check that you are not syncing your devices both over iCloud and through iTunes.
You can do this by clicking on your device and looking under the "Sync Contacts" and "Sync Calendars" under the "Info" section. Much to my dismay, SyncServices is just broken as heck, and syncing local calendars just does not work well. Apple is forcing us all into the cloud, where my personal data is now available to the masses, but that's another issue entirely and I digress.
After doing these steps, I have not seen mingler or SyncServices show up as using more than a couple percent CPU for a few seconds. No more fans at maximum, no more 100% CPU.