Did you use photo stream before jailbreaking?
If so, you'll be able to copy your pictures on your computer from the "My Photo Stream"-folder to the "uploads"-folder. Then everything should appear on your iphone again...
Not exactly the same problem, but is anyone else unable to click and drag pics to/from iP4S? I Used to do this on my iP4, but I haven't been able to do it on the 4S.