Sometimes you find things out the hard way. I own a HTC Desire which I upgraded in good faith to Android 2.2 (FroYo) and all has been well.
However more recently the Desire has been running low on memory due to the number of applications and messages I had on the phone.
I deleted a couple of message threads that had over 1000 messages in which helped a bit as well as deleting a few apps I had used only a couple of times and moving some to the SD card (now available through Android 2.2).
For some reason the phone went a bit mad on me yesterday and decided to delete ALL my messages! I thought that’s a bit strange. Re-booted a couple of times still to find the messages still were not appearing.
Not that it was a big thing for me to keep old messages but there were some important ones. A bit perplexed because I was under the impression that my messages were backed up automatically by the device to the memory card. I had used this auto backup several times before and it worked perfectly.
HOWEVER – A call to HTC has confirmed – Android 2.2 on the HTC Desire DOES NOT automatically backup your device. The ONLY backup is the sync to Google for your email and contacts! Apparently this is because when the roll out took place the backup facility was not complete and HTC are working on a solution.
Therefore BE VERY AWARE to use 3rd party or alternative backup solution as programme settings, home screen configurations and messages WILL now be lost if the device is reset as there is NO auto-backup.

This is by no means a plug for the offer we have with WaveSecure at the moment, BUT you really should if you are an Android 2.2 user on the Desire consider using their backup services. As you can see from the images below, it backs up your SMS – Guess what I am now installing on my device?

I will let you know when I hear from HTC of a fix.
[...] UPDATE 08/09/2010 – PLEASE NOTE: THE AUTO-BACKUP FACILITY HAS BEEN DISABLED – READ MORE HERE [...]