If you get “Cannot connect to iTunes store” when doing updates but all other store functions seem to work (browsing, purchasing and downloading apps), then try this weird trick that seems to solve the problem for a lot of people. It definitely worked for my 1st generation iPad.
Go to Settings -> General -> Date & Time and turn off “Set Automatically”. Then manually set your date a few years in the future. Go back to the iTunes store app and try to do updates. It will tell you that there is a security issue and you should check your date and time. Now go back to settings again and turn the automatic date back on. Return to the store app again and try to install updates. It should work now.
Other things to try are:
- Logging off and back on with your store account
- Rebooting the iPad
- Making sure that all of the apps that you have installed and you are trying to update were installed from the same account that you are currently using now.
Hope this helps…