Using Blackberry without BIS

[bbreiss]

Hey,
I have BB 9780 and I have a regular data plan on my carrier without BIS.

I understood that by changing the SB on my BB I'll be able to use blackberry services (or at least surfing on my carrier data APN).
Without changing anything I'm now able to use the wap APN normally, but even by changing the APN on the TCP/IP option nothing happens.

I have BB desktop manager on my PC, and also BBSAK, vnbbUtils and Magic Berry.
I created a backup using desktop manager and opend it with Magic Berry, I saw some Service books but not all of the SB on my device showed up.

Is there any way to really change the APN from blackberry.net to my carrier's one?

Thanks.