I can't answer for premiere 6.5 as i use 1.5 but maybe its the same.
In the preferences you need to unclick the "resize stills" checkbox.
Then when you drag the photos into the timeline they remain full size. In the monitor window you can zoom out to 25% which should allow you to see the photo over the video window.
(Mind you i'm a total newbie to this so could be wrong!)