That's a really helpful suggestion. I will do that this evening once my inks arrive. As I say I can't do it before because I've run out.
Re a plugged cartridge, the nozzle tests came back fine so I'm pretty sure it isn't that. The more I consider it the more I'm concluding I've set it up wrong in Lion. Epson were due to mail me some information but they haven't. They're not terribly effective over her but I will contact them again today and see what happened.
In the meantime the preview tip should clarify one potential issue.