If you take the battery out of your phone and put it back in and that should reset it...this can be caused by leaving your phone on all the time ..it causes display problems sometimes so maybe turn the phone of when you charge it or something.

I also have this phone - if it's under warranty take it back - or at least get advice from where you purchased it from....
They may be able to repair it or at least give you some advice on how to reset it - have you got the manual??
If not I'll have a look in mine - I'm sure there is a way to reset the whole phone...

ive got an LG U8120..and yesterday for no apparent reason it froze..i couldnt even switch it off so i removed the battery and turned it back on..and now,all the labels for different menu's etc, are all mixed up...for example-where it normally says contacts it says 'defelct'...all the menu options are confused(tools where messages is etc.none are in the right place), and then the options within each menu option are confused...
if you know of anyway i can fix this other than throwing it at a brick wall, please help
thanks