iPod touch doesn't sync automatically?

Summary Pane
Select “Open iTunes when this iPod is connected” to have iTunes open and sync iPod touch automatically whenever you connect it to your computer. Deselect this option if you want to sync only by clicking the Sync button in iTunes. For more information about preventing automatic syncing, see “Preventing Automatic Syncing” on page 13.

Preventing Automatic Syncing
You can prevent iPod touch from syncing automatically when you connect iPod touch to a >computer other than the one you usually sync with.
Turn off automatic syncing for iPod touch: Connect iPod touch to your computer.
In iTunes, select iPod touch in the sidebar, then click the Summary tab. Deselect “Open iTunes >when this iPod is connected.” You can still sync by clicking the Sync button.
Prevent automatic syncing for all iPhones and iPods: In iTunes choose iTunes > Preferences (on a Mac) or Edit > Preferences (on a PC), click Devices, and select “Disable automatic syncing for all iPhones and iPods.”
If this checkbox is selected, iPod touch won’t sync automatically, even if “Open iTunes when this iPod is connected” is selected in the Summary pane.
Prevent automatic syncing one time, without changing settings: Open iTunes, connect iPod touch to your computer, then press and hold Command-Option (on a Mac) or Shift-Control (on a PC) until you see iPod touch appear in the sidebar.
Sync manually: In iTunes, select iPod touch in the sidebar, then click Sync in the bottom-right corner of the window. Or, if you’ve changed any sync settings, click Apply