Lost all contacts after iOS 4.3 update [iPhone 4]

The same thing happened to me!

I want to add that it put outlook contacts I never wanted on my phone and have never had. This is a itunes or new OS problem that a few of my friends have had also. I have reported it as such to Mashable, Fox New, CNN, Tech Crunch and hopefully they will put Apple on blast for this huge F&*^k up!

I found that upon upgrading to 4.3, the "Sync Addressbook Contacts" setting was deselected. Re-selecting it restored the contacts.

I had the same experience as RandyCPU, updated to 4.3 yesterday, all contacts disappeared but all other information still there, photos, texts, recent calls but no names etc. I too found that my phone was not backing up contacts and I only had the info from my changeover to the iphone4 in December. I asked if I could set it to back-up on syncing and was told it did it automatically but this is obviously not the case, I was then told that I would have to do it manually. Apple could only suggest restoring the December back-up but I have now lost everything loaded on the phone since then, they also advised that I was the only example of this problem. Very unhappy and still no idea why it happened.

I was on the phone with support for 2 hours last night and it still is not resolved. I was able to get most of them back back reverting to a previous backup, but still many are missing. The problem is I dont what is missing-there is no rhyme or reason to which ones are gone.
This is a major mess and it needs to be resolved immediatlly

As I am searching for my missing contacts, it is appearing as though the 4.3 update deleted all of the ones I use most. Anyone else finding that?

Same issue here........ can't get it back. Not good enough really Apple!!

Same here, with 3GS

I just did the update and lost contacts. What I found interesting as well is when I went to my favorites and the phone numbers were there, I just went to each number to add as new contact and pictures were showing up that were on others contact information. This is crazy and shocks me honestly, since I have had Apple products my entire adult life. You can go to iTunes preferences and see the latest back ups for the phone but you can't do anything with them except delete them. What a pain in the butt.

I also lost all my phone contacts when I upgraded to iOS 4.3. This seems to be a VERY "BUGGY" upgrade. Apple had better come up with a fix for all the problems this new iOS has caused!

My 3gs has same problem. Updated to iOS 4.3 and have lost all contacts ..... my advice is don't update if you haven't already .... now I'm stuffed, thanks very much Apple !!

This seems to have happened to me today, with one major exception...I am still on 4.1, and was not syncing,updating, or changing anything. I got a phone call from a friend, and his number showed up without his contact info. So when I went to look at my contacts, they were all gone. My favorites still have phone numbers, but no names. And of those contacts I have manually reentered, they now show the wrong person in the picture whenever someone calls. Syncing has had no effect. All I can say is that this seriously *****!

I've also just discovered more by chance that all my contacts had been wiped, which I presume is due to the upgrade to iTunes 10.2 and iOS 4.3. Thanks a bunch, Apple.

I sincerely hope that they are somewhere to be found, as I certainly do not have all the contacts available in written form...

Any ideas how this can be undone?