6230i won't connect to wap via GPRS on O2 PAYG

I'm sure the settings are correct, I had them sent from the O2 website.

I had no problems using my 7250i on dial up WAP or GPRS.
(GPRS was a paid for option.)
I get 300 free minutes per month of WAP dial up.

My 6230i with the same sim card can't do dial up WAP. Not an option, but
won't connect via the paid for GPRS service.

I thought i'd ask here before phoning O2.
It's cheaper ;-)