I got this error and it turned out to be a networking issue around an ip address conflict leading to TCP session failure during the download. TCP session failure can also result from excessive TCP windowing resulting from poor or busy networks
If you have to use a 3g network try ainly updating the apps one at a time instead of having auto-download try and get them all at once.
I would recommend:
a. use wireless
b. move somewhere else and reboot the device
unfortunately DHCP leases tend to persist for over a week so try not connecting to the affected network for a period of time. I would not recommend re-installing the device or changing the play account as this will not fix this kind of problem