My otherhalf has a Samsung U600 and she has recently been having a few problems when she goes to write a text, it basically freezes when she hits space after the first word. It seemed to come and go and last weekend it just got worse.
A bit of googling can go a long way but most of the “fixes” were either: take it back to the shop (normally a very good idea, but out of warrant), just not use the T9 predictive text as this is the route of the problem (works but I think she wants predictive text!), or upgrade the firmware (I never like doing things like this and the posts suggested it didn’t always get rid of the issue).
I thought there must be a restore factory setting option – and indeed there is but the one on the phone just puts the look back to default so you need to do something a bit fancier. Essentially you just give it a command. Note: make sure you have backed up everything off your phone this will delete everything that is on the phone (but not the stuff on the sim card). Just type in: *2767*3855# which resets the phone back to factory default settings – job done, all working.