Why won't my song purchased from iTunes download to my iPad 2?

I own a 64GB iPad 2 + 3G which has been updated to iOS 5.0. I do not use wifi. I rely on 3G.

I should have lots of memory left as I have not downloaded or saved barely anything.

I have successfully downloaded a song just the other day from iTunes without any problem.

When I purchased a new song from iTunes today, however, I got the message "Unable to download song. 'You be Killin em' Could not be downloaded at this time."

I was offered a choice between DONE and RETRY. When I tap on RETRY, the downloading begins anew. I see the MB numbers and time remaining changing. The blue line is inching across the status bar. Then after several minutes, I get the same message. I have tried this several times this evening to no avail.

I tried tapping DONE and then starting the download again, but same thing happens.

I found a posting by someone who had the same problem, but with an iPhone. S/he was able to resolve it by tapping RETRY and then quickly tapping pause and starting it again. I tried this on my iPad 2 with no luck.

I do not have a laptop or desktop, this is my only device. (Apple Store did the set up and upgrades for me.) Thus, I hope there is a solution that does not involve any kind of synching with another device to get it from iTunes.

I am not a big music listener; Never had the iPod either. Starting to regret trying to download songs (this would have been my third song only).

It can't be an issue with 3G, as the song is less than 20MB.

I would appreciate any pointers. Thanks!