Problem sync iPod with OS X Lion!

I upgraded to Lion OSX, & iTunes 10.5.2. My iPod,I think is the 2G (Latest Version update 4.2.1). Now I can’t sync my apps or anything & I get this message: “iTunes cannot sync apps to the iPod ???…???s iPod??? because the apps installed on the iPod could not be determined.”. What can I do now??!! Does this mean that I will never sync my apps anymore coz my iPod is an old version??!! Any help plzzzz!
Note: iTunes recognizes my iPod, problem is only sync.
Thanks in advance.