I have a samsung wave 525 phone which has started behaving strangely - keeps alternating between samsung start up screen and the O2 screen and nothing else happens no matter how many buttons I press! Anyone know what's going on?

Hello

It seems as if you are having a firmware problem. Do you remember what you were doing before it failed to startup? I would recommend calling O2 and taking it into them as the other methods available to fix it could affect your warranty (E.G flashing your firmware). However I must warn you if you take it in and they replace your firmware you will most likely lose all of your data unless you have backed it up using your phone software.