Sudden loss of contacts on my Samsung Galaxy S - running Gingerbread I have recently experienced that all my phone contacts suddenly disappeared from my internal phone memory. 

I could still see the 2 contacts that were on my SIM-card, and I have no contacts on my external SD-card.

I have looked through the different contact display options under settings, and they were all on.

The contacts disappeared without me installing or deleting anything, or any other provocation. And while I was browsing through my call log, I could see the contact names being replaced by the underlying phone no, like a slow delete, very frustrating.

I tried to Google it, and found that this has happened to many other Android users (and not just Samsung phones), but I couldn't find a suitable solution to the problem anywhere. 

It's not catastrophic since I have all my contacts synchronized with Outlook, although, I will be losing the contacts added after my last sync. 

But I would really like to avoid to have this happen again in the future, and if possible recover my lost contacts. 

Does anyone have an idea of what has happened, what to do about it and how to avoid it in the future...?
I don't know why it happened, but a good way to prevent it from happening again is to set your contacts to sync with your Google account. This way whenever you add a new contact, it will be uploaded, and if the phone loses your contacts again, you probably won't even notice it, as they will be automatically downloaded back to your phone.