Problems downloading songs from the Guitar Hero 5 Music Store

I tried to download some songs from the Music Store and also tried to download the Guitar Hero World Tour Downloadable Content Update from Options->Import Songs but neither the songs or the update downloaded fully- the downloading seemed to stall and could not be resumed. So I quit the game and went into the Download List in the PS3 Network options, they were all listed as still downloading but they were not making any progress - the update was stalled at 42% and the songs were all stalled at 1%, 7% etc.

So I thought the only thing to do would be to delete them from the Download List and download them again. I deleted them but now it won't let me re-download them- when I go into the Music Store to download them again, it tells me that I've bought the tracks alright but doesn't give me a download option- will it only allow me to download them once after I buy them? There isn't even an option to buy them a 2nd time either.

Likewise with the update, when I try to download that again it tells me that I've already purchased it and I should check my Download List, but the download list is now empty because I deleted them all because they had stalled.

Is there any way I can download the songs or update again?

Cheers!