Why does my Galaxy S keep corrupting and resetting? My Samsung Galaxy S was working well, but about a month ago it turned itself off, and upon restarting went through the initial setup again (language, keyboard, etc.). At the same time, lots of apps started to fail, and were force closed and relaunched by the OS (Swiftkey, Agenda Widget, and others). All my other data was intact.

Eventually, I reset the phone (losing all the texts and my Angry Birds progress :o) and reinstalled the apps and set up my sync accounts again.

The phone repeated this process three times in a week, so I requested a return, but then as I was waiting for a returns envelope, everything seemed to be fine. I decided to see if it was a glitch and all was well until this afternoon, when it turned off again (I checked and the battery was pretty full) and has started doing the application force closes again.

Running Froyo from the official Samsung update via Kies.

Any theories?

Thanks.
If it keeps doing this even though you've done a factory reset, I would just go ahead and exchange for a new one.  You could, however, try flashing a ROM via Odin with re-partition, to completely start fresh.  Instructions (assuming you have the i9000 model) are below.

Go to this XDA thread and download the newest firmware for your region (caveat: if you're concerned about warranty, you don't want to use the 2.3 firmware since it wasn't officially released.  To be safest, flash the exact version you already have).  Download Odin for Windows (search for "Heimdall" if you are on Linux).  Then do the following:


Put your phone into Download mode

Remove the battery
Hold VolumeDown plus the Home key plus Power.  While holding,

Reinsert the battery.
Release the power button, still holding the others, about 1 second after the white "GT-I9000" text appears.
After a few seconds a yellow triangle with an android in it should appear, this is Download Mode.  If it doesn't, try this again while holding Power the whole time.


Start up Odin.
Attach the phone to your PC via USB so that Odin recognizes it.
Load the .zip file you downloaded (the ROM/firmware) into the PDA field of Odin.
Load the 512 .pit file into the PIT field of Odin.
Check "Re-partition".
Hit Start.  Odin will tell you when it's done; if it fails, reboot your phone and try again.  (This happens occasionally).


Note that if you need to back anything up, you should do that beforehand and save the backup to your PC, since everything (except probably the external SD card) will be wiped on the phone.  Also note that you do this at your own risk; Odin is very powerful and misusing it can damage your phone.  I've used it dozens of times myself safely.