Hi Stu, fisrtly, welcome to WPF.
Secondly, you say you've gone straight to manual. When taking the pictures in manual mode, how were you deciding which settings to use? Was the camera's metering system telling you that you would be correctly exposed when you used the settings you did?
Even though you are in manual mode, the camera's metering system will still be advising you of its idea of how "correct" the exposure will be given the settings you are dialling in. It would help if you could take a picture in manual mode (presumably black), and the same scene, in the same conditions, in fully auto Program mode, and post them both here. We can then look at the settings each mode has used, and hopefully see why one is black.
For a tutorial on understanding manual exposure mode, and how the settings interact with each other, see this thread:
http://www.worldphotographyforum.com...read.php?t=125
Duncan