iPod touch Itunes - Problems buying songs

[ffc]

If I try and purchase a song on my touch I get the message

"Your account information has changed. Go to the iTunes store on your computer and update your billing info."

But I can buy songs fine from my computer fine and no information has changed?

Any ideas??

 

[PowerFullMac]

Plug your iPod in to your computer then wait for it to sync with iTunes, unplug it then try the Music Store again.

 

[ffc]

Have tried this my ipod is all fully synced has been for a few weeks, I have also tried purchasing songs while connected to the computer?