without somewhat more specific info its difficult to say but here's some general thoughts.
Which NERO are you running if Nero 6 uninstall and reinstall
When you call up Nero Burning ROM does it identify your burner in the bottom right or does it say Image recorder - if the latter the program isn't recognising your burner
What picture file format are you using JPEG should be fine but if BMP beware of file size
Bit general but hope it helps if not post back with info on OS CD burner Nero program etc