My Sony Ericsson P910 will not let me access the internet because all settings relating to the WAP connection to use are disabled so I can't change them from the Vodafone ones to the O2 ones.

The handset is a Vodafone handset but it is unlocked and works perfectly with an O2 SIM card.

Is there anything I can do in the file system to change those?

I noticed that I cannot change the internet start page and that it is pointing to somewhere on A: (ROM) so I am not very hopeful.