Why are my iTunes movies failing to download?

I have tried unsuccessfully to download two movies via iTunes. My broadband speed is not an issue as the movies appeared to download onto my iPad but just as they start 'processing' it fails and gives me the choice to either select Done or Retry (this doesn't work).

Web advice suggested turning off JavaScript, this didn't work. I was also recommended to log out of iTunes account and reboot the device, log back in etc - still nothing.

Can anyone help please?

Thank you