Mark's right, it's your monitor. Here's my blog entries on the topic:
http://www.danecreek.com/blog/2010/02/17/monitor-brightness-and-dark-prints.html
http://www.danecreek.com/blog/2010/05/10/monitor-brightness-and-dark-prints-part-2.html
Neil
Hi Neil, If I'm the "Mark" you are referring to, I didn't quite say it is his monitor, but by pointing him to Andrew's article where monitor brightness is the one of THE MAJOR highlighted issues, indirectly I suppose I did. But in point of fact the OP has told us so little about any of this that it's impossible to provide useful advice. We have no idea what the original scan really looks like, whether indeed he does calibrate and profile his monitor and his printer, and if so at what settings, what the ambient viewing conditions are, what post-scan workflow was used apart from colour management, etc. etc. etc. etc.
This kind of thing happens so often on in forums that I can't help but observing it's fine to come here asking for guidance from other members, but there is a minimum amount of information we need in order to be useful. I have no doubt in many cases people don't know enough about the topic to understand what others need to be told. In all such cases, a certain amount of self-education is really the best course before coming onto forums posting such broad unanswerable questions. One needs enough basic education in the subject to at least know how to ask the questions in a way that may elicit solutions to problems. And there are TONS of resources available right on this website, a lot free, some pay, to do exactly that.