Success at last
I had the same problem, and spent DAYS on it. Here are the details:
I could sync Outlook contacts with no issues, but no matter what I tried I could not get one calendar appointment to show up on the iPhone. Itunes would sync, and even take a while processing "Syncing Calendar", but display no errors.
* This is an iPhone 3g, firmware 2.0.5A347
* Itunes 7.7.043
* I am a Microsoft Exchange client, so do NOT use PST files to store my mail
* Would not work with Outlook 2003 SP3 -or- Outlook 2007 SP1, -or- Entourage 2008 (Mac)
I tried everything I could find on the forums, including:
* full iPhone restore,
* Creating new Outlook profiles
* Creating new Windows User profile
* Clearing Sync History
* Uninstall / Reinstall Itunes
* Disable all third-party plug-ins in Outlook
* Set outlook security to none
* I had the appropriate plug-ins for Outlook
* Tried this all on a separate PC as well - no joy
What turned out to be causing the issue were Outlook recurring appointments which had atypical characters in the name: example
JESICA'S B-DAY<<Free>>
Steve's B-day<<Free>><<Free>><<Free>><<Free>>
I have been using some sort of PDA for around a decade, and carrying a lot of these recurring appointment over for almost as long. Somewhere along the way whatever sync software (ActiveSync, PalmSync) changed the formatting of the appointment itself and generated the <> symbols. When I deleted these recurring appointments and re-synced I saw all appointments show up.
Here is what I recommend:
1. First, if you are having your mail delivered to a .PST file then please ensure that you have followed the procedure to properly format/replace your PST, along with all of the other easy suggestions related to this issue.
2. Back up your entire calendar before doing this. The easiest way for me in 2007 was to highlight the calendar in the left-pane in Outlook, click File - Save As and choose .ics as the format.
3. Click More Options. For Date Range, select Whole Calendar. For detail, select Full Details. Click the Show button and check both boxes, and save this someplace you won't lose it.
4. In your Outlook Calendar, sort the entries by clicking View - Current View - By Category. Expand as necessary and sort the entries by the "Recurrence Pattern" column. Look for any entries that contain alphanumerics or other novel characters in the titles. Delete all of these odd (remember, you have a backup) entries.
5. Open up Itunes, access Preferences - Sync tab. Click the button to reset sync history, then try to sync your iPhone again.
Any calendar entries show up? If not, delete ALL reccuring appointments and try the sync again this time. If this works, you'll need to do some more analysis on those specific appointments to see which ones are causing the issue.
Good Luck