ipod photo cache is empty and thus no photos are synced on ipod?

the ipod photo cache folder is empty and has no contents in it and thus no photos are shown in ipod. bt when i sync photos frm itunes the photo tab in itunes shows space occupied in the capacity bar. and the step 4 doesnt get completed wen syncin and jumps to finishing sync directly...

hw can i add photos nw?

thanks for the help..

cheers.