I would first check with your carrier. Normally when a Blackberry goes into that lower case 'gprs' mode, that means the settings are not proper on the account side. They need to refresh the network and possibly check into the Data settings for your BB.
I had a similar issue like that back when I initially got with a Blackberry and Data Plan. The rep from Cingular Data Support didn't know what the heezey he was doing.. so I Called back an hour later. Got someone who knew it and got the problem fixed. Running smoothly for the last 4 months now.