iphone 3g receiving texts hours late

[fabemmy]

Can anyone help me with this problem

I have been receiving my text messages up to 6 hours late on my iphone 3g.
I changed my sim card just in case there was a falut on that.
I have tried taking the dust out of the sim card slot and I have tried switching the iphone off and back on again.
The signal on the iphone as always got full bars and I can call out and receive calls fine and I can send texts fine as well.

Also I get a message come up on the screen that says "I am not subscrbed to a data cellar network" this message comes all a few times in just one day.

Any ideas whats wrong.

[fo3nix]

Take it to O2 and find out.

I assume it's not been jailbroken?

[fabemmy]

No it asnt been jailbroken