Android :: How To High Low Network Over Cell?

So my app works well in the emulator in various run configurations and on the device when the device is connected to WiFi. But when I switch off the WiFi on the device, the code that goes out to the network takes forever and then times out (i.e. doesn't return any data). Other people have reported this as well. I also notice that no data is going out or coming in when I look at the little up and down arrows on the 3G icon in the status bar on the G1. I am assuming that the Java code I am using should work for both types of connections, right? I mean, do I need to account for the fact that cell data network is very slow with high latencies i.e. pre-cache my data etc?