Actually the saga continues...
After getting everything sorted into order and displaying correctly on the iPad, I deleted just one photo on the XP computer and ran iTunes again. Well it recognised that something had changed and made a change on the iPad.
Unfortunately, it effectively reshuffled that particular album incorrectly. Duh Apple!, it only had one deletion to do and that meant that was just a two second gap in the sequence of the EXIF modified dates of 24 pictures.
The solution here was to run the EXIF Date Changer yet again over the whole directory and then run iTunes again. This time itunes decided to send all the pictures in that direcory/album again and this time got the sort right again.
Apple, you have a major problem with your iPod Photo cache program. It can't always recalculate a folder/album when it knows that it needs to (and one has to manually delete all F00, F01, F02 etc directories) and it can't even handle the simple deletion of one photo. You need to do some serious investigative work.
To those users who earlier on commented on a reluctance to change the EXIF data, there is an option in this program to retain a copy of the original date, there is also by default, an option to write a fesh set of images with the modified date in to a subdirectory. You can then gather these up and put them in the iTunes download area.
Actually, whilst it may be logical for the Apple's iPod Photo Cache to optimise the images for the various devices, Apple needs to delete the sorting routine out of it and put it directly on the iOS of each device.with user changeable sort options in the device's settings.