Foo:Foo:Brendan: Try wiping the delvik cache in advanced... And also the other cache.
If not you will have to do a wipe/factory reset and load your contacts etc again from gmail.
Okay, will select the "wipe cache partition" option.
I haven't rooted my phone nor flashed non-stock f/w.
Alas, no luck with that. How do I access "Advanced"?
Only available on rooted phones...
I think your only option now is to factory reset the phone. and reinstall everything from the market and gmail..
Hope you have a wifi connection handy. Or atleast a lot of data left on your phone. Still, if it won't boot it's not like you can use it anyway at the moment... (e.g. if you don't have a good data connection the phone will still work, but without your contact details and apps).
I think it must have been some rouge app or maybe a os bug. These phones are computers, and we all know of the reliability of computers......................
I suggest you root your phone and do a nandroid backup (see my guide in the sig), then install a custom rom. Custom roms typically are superior to carrier supplied roms. Samsung desinged the device to be flashable like this, and even supplied some to noted custom rom developers for free.
But it does void your warranty.
But they have to prove that's what you did in case of a warranty claim... not always easy.