Can't synch photos to computer (and I've tried the obvious stuff). Help!

My wife's iPhone 5 contains roughly 1,500 photos. When I try to synch it to her computer via iCloud only about 20 pictures transfer. I've read the support forums and tried the obviously things like turning photo stream on (it was) but still no luck. I can manually download the photos to her computer but I was hoping to use the synch function so that they would automatically do so when connected to her computer.

My iPhone 5, on the other hand, synchs just fine. All the settings appear to be the same and the only difference is that I'm using a Windows 7 machine while my wife has a Windows 8 machine.

Any suggestions?