For reference for other Vista-users having the same issue:
1) Transfer the pictures you were trying to sync to the iPhone to a FAT32 formatted drive, such as a USB flash drive or external HDD. Make sure to remember the location you save them at.
2) Put your iPhone in its cradle and open iTunes. Go to the "Photos" tab.
3) Uncheck the box to the left of the words "Sync photos from:". It will ask you if you want to delete the photos on your iPhone that have been synced. Yes, you want to erase the demon-spawn pictures that Vista and iPhone have created, to replace them with your original, pristine pictures. In short: YES. YES you want to delete the ones on your iPhone.
4) Sync your iPhone, erasing the pictures.
5) Now hit the drop-down box next to the top where it says "Sync photos from:". Change this to the FAT32 location you transferred your pictures to.
6) Sync again. If you're lucky (like me) ALL of your pictures should be in the iPhone, and in their original glory.
This is the process I used. If you lose all your pictures because they weren't backed up somewhere, or you messed up the process, or because I typed it incorrectly, I can't be held liable. To the best of my knowledge, this is what fixed my photos.
Good luck!