Exchange 2007 service pack and Rollup Update version? iPhone is updating over the wireless (local LAN to Exchange server) or through 3G/4G carrier wireless? Have you looked at the calendar in OWA to see if the changes you make are valid? If you add a meeting in OWA will it show on the iPhone and if you add one to the iPhone does it show up in OWA? That's where I would start.JAUCG

What were the results of your test?JAUCG

My problem: Exchange Outlook calendar will sync one-way only. Exchange Outlook email syncs fine both ways. When I try to add an event on iphone or ipad and choose the Exchange calendar, the screen freezes and the event is not added. If I add an event on Outlook calendar, the event is synced to iphone and ipad fine. My devices: iphone 4 iOS 5.0.1 (9A405) - used to work fine, recent software update. I also used google sync pre-iphone for my ipod (forwarded the Outlook calendar to a new google account, synced that to my ipod). I no longer use that software on my new PC, but since I'm using exchange with the iphone, didn't think I needed to. ipad2 iOS 5.0.1 (9A405) What I use: Microsoft Outlook 2011 Exchange 2007 A new work computer with ZERO admin privileges (can't even update Java...). My problem started around this time, which is the same time I upgraded iOS. iCloud is OFF for calendars. Because I have one-way sync, I have not deleted anything yet, hoping I have a setting wrong. Do you think the issue has to do with a corrupted .pst (outlook calendar) file? Thanks so much in advance. I'm stumped!

I'm leaning toward #3. I ran the test at work -- the calendar entry I put on my iPhone appeared seamlessly on Outlook via the campus wireless system. The iPhone did not freeze, as was the initial issue. I turned off wireless and tested using 3G. It took longer, but the entry appeared on my Outlook calendar as well. It's interesting to note that I did not restart my iPhone at any point during this time, nor did I change any settings. I am solutionless, but I am also problemless. If anyone else ever has this issue, though, at least there are some good steps here to narrow down the problem.

Exchange 2007 service pack and Rollup Update version? iPhone is updating over the wireless (local LAN to Exchange server) or through 3G/4G carrier wireless? Have you looked at the calendar in OWA to see if the changes you make are valid? If you add a meeting in OWA will it show on the iPhone and if you add one to the iPhone does it show up in OWA? That's where I would start.JAUCG

Well, I am glad to heard that everything is working. Sad to say that sometimes these issues do pop-up with no obvious solution. Let us know if you have this issue repeat itself.JAUCG

Thanks for the suggestions. Your comments were helpful in narrowing down my problem. I was able to create an event on my iphone (without it freezing) that appeared in OWA while at home via my home wireless and vice versa. It also appeared on my Outlook calendar when I connected to check via VPN. I disconnected from wireless and the test was successful in all ways via 3G as well. Given that my iPhone froze each time I tried to add an event to the Exchange calendar previously, I have two theories 1) The test worked while checking Outook via my VPN but will not work on my local Outlook client when I test it tomorrow, indicating that the issue is at the client and not server level; or 2) something magical happened in two days to fix my problem. If theory #1 turns out to be right, the problem would be with my calendar settings/file because all other Exchange data transmits both ways successfully, right? This could be the case, since I just got a new computer and calendar settings were ported (for lack of a better word). And theory #2 doesn't answer the question of why events I added on my iphone were not added to Outlook when connected to my home wireless network, does it? They might have been added to OWA this entire time (and were prevented from appearing on Outlook), but I hadn't looked until now. This also suggest a local calendar settings issue. I'm really just hoping for #3 though, magic. Thanks for letting me talk it through!