What I meant was that the network mode was set to "Dual", which defaulted to 3G. I had the actual data connection active for around 2 hours at most (less than 1/3rd of the total period). For good measure, I have since downloaded the 3G/2G mode applet and have set the network mode to 2G.

About the powertop vs zzztop results, the inconsistencies in the C4 state are quite consistent. They remain so, even after flashing.

This appears on my dmesg, despite attempts to disable the bluetooth modules. Could it point to something?