Why can't I uncheck/check music on my device in itunes anymore?

[Tink-dsi]

In the library part of itunes I can uncheck/check everything, but i cant edit anything in the "device" section, i could before....any ideas? thanks in advance :)

[Youngbinks]

I can't remember ever being able to select or unselect songs within the device category before. You might be able to do that if you enable the iPod (iPhone) for disk use but I am not entirely sure.

[Tink-dsi]

im a new user to the iphone and itunes, only had it about a week so still figuring a lot out on it, my other half confirmed i wasnt seeing things and i could actually edit and move music directly into the device,now i cant. I also then figured out that if you do this you couldnt move the music back to the library....so i guess its a blessing in disguise really..