3.0 data drops affter some time but shows 3g icon

Is anyone having same kind of problems with 3.0.
My data connection gprs or 3g doesnt work affter some time of reset, but still shows the 3g or gprs icon and on sbsettings I have data ip.
Only fix I have found is to reset the phone.

The data connection stops working quicker if I have push notification enabled.
eg. i notice that data is not working anymore if I go to safari and try to open google.com it just keeps loading and doesnt stop and the load bar wont move no notificatin or anything that page cant be loaded.
I bet it's problem of the new baseband, I have the same problem on iphone 3g and 3gs.

Help would be apriciated.

UPDATE.

I think i fixed my problem I edited carrier.plist and I found some bugs what apple has left for for vodafone greece carrier info.
I'm using vodafone cu prepaid service with 130mb per month.

if someone is having same kind of problem I'm happy to help just pm me.