Notes being truncated

Hi all,

I regularly make notes in the Notes app on my iPhone 4S. I have two main notes files which change on a regular basis and a third which doesn't change as frequently.

I noticed that after syncing my phone two days ago, most of the text in the two main notes has disappeared.

The first line of each note is still visible when I am in the initial Notes screen both on my phone and in Outlook. But when I click on the note to see the detail, only the first letter of the note appears - and nothing else.

Usually, iTunes will invite me to decide which version of notes to keep - on my phone or on my computer - but it didn't do this the last time it synced. And now the text in those notes files is gone both on my iPhone and in Outlook.

Annoyingly, the third, less used notes file, has remained the same - it's the one notes file I don't really need!

How can I avoid this in future? And is the data from those two main notes now totally lost or could there be a backup somewhere?

For your info:
- iPhone 4S
- iOS 5
- Windows 7
- iTunes 10.7.0.21
- Microsoft Outlook 2007