That's curious, because I don't think the iTunes sync has never copied iPhone photos back to a computer (see support link below, which clearly suggests photo syncing is one-way). But, depending upon how your computer is set up, you can have a variety of other methods of importing photos back to your computer. You can manually fire up explorer, and you'll see the iPhone listed there under "Computer" and you can copy photos that way. Or if you go to "Control Panel\Hardware and Sound\AutoPlay", you can tell your computer what to do when you insert your iPhone, e.g. import into your favorite program.
http://support.apple.com/kb/HT1386