The files that you say are syncing again - even though they are already on the iPad - will always sync again unless you deselect them in iTunes in which case they will be removed from the iPad. That's how the sync works.
I'm guessing that you may have a corrupt photo or image that is causing the sync to fail or quit. You might want to try removing all of your photos by deselecting them in iTunes then sync - and try adding them back on to the iPad in smaller groups until you are able to nail down the troublesome photo, album or event that causes the sync to stop.
If you want to try removing the photos as suggested, you may want to repeat the remove the iPod photo cache folder one more time before you begin resyncing the photos back onto the iPad.
There are other things that you could try, like deleting your iPad backup - on your computer, launch iTunes and go to iTunes>Preferences>Devices>Your iPad's name and then select delete back up. Quit iTunes and then try to sync again.
Or something a little less invasive that may or may not work - but it will harm nothing - try resetting your iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple logo appears - ignore the red slider - let go of the buttons. Then try to sync again.