ack-I lost all (but one) images when upgrading

I upgraded from 1.2.2 to 1.5.2 today as a recommended intermediate step before going all the way to the newest version. It’s gone okay except I have lost all but one of the images that were associated with the posts. Almost all posts had images included, many had several. I used the Exhibit plug-in to upload most, but not all, of them.(The one photo that mysteriously does display was done with Exhibit.} The images are on the server but the posts no longer seem to reference them. I have no idea where to start to troubleshoot this. Help will be VERY appreciated!

Update: My problem still exists but as I delve deeper into my site I find more photos that display. Not many but some. No idea why some do and some don’t though… am looking forward to some suggestions as to what I should do next.