Ipod (Touch my apps working! Help?! Please(:

Hey,
I'm trying to download apps onto my ipod (Touch) But i need to download the update 4.0 but every time i try this it comes up with an error and 4 hours seems like an unusually long time to download an update? - But i did it none the less and its not working. All i want to do is download the lastest free apps. (And yes i have ticked the box under applications that says 'Sync Applications'
Help Please?!
x