Dave,
I am sure this has been discussed before but the search for "Topaz" brings nothing up.
How do you correct for the change to old Topaz processed images that have had their Capture time altered?
Until I do a Google search for "Topaz processed images", I don't know what a Topaz processed image is.
If the Adjust Capture Dates and Times dialog is unable to adjust the capture time of your images, it is likely due to a missing EXIF capture date tag. PM won't insert one if it doesn't exist. If the tag doesn't exist then PM will use the creation date of the file (if the filesystem supports it, not all do) or failing that, PM will use the modification date of the file as the capture date.
-Kirk