Well, thats something I didnt notice but may explain some of the quirkiness Ive seen. I have my cell on Wifi most of the time (home and work) and only go to 3G when Im out and about (no 4G here or planned for here). The stupid thing wouldnt get email all day and then out of the blue pop, one would show up. I will play with the wifi/3g and see if i see any patterns too.
I di d a factory reset on the first GB release and it didnt fix it. Please let us know if you do a reset and if it works before I go through that again.
One other idea, my emails worked until they forced facebook and tunewiki to be active all the time. I used to be able to kill those programs in froyo but now they just come right back in GB. Yes, I am reaching for straws