Is this the problem?
Does the iPod connect to other networks?
- Reset the iPod. Nothing will be lost
Reset iPod touch: Hold down the On/Off button and the Home button at the same time for at
least ten seconds, until the Apple logo appears.
- Power off and then back on the router
- Reset network settings: Settings>GeneralReset>Reset Network Settings
- Restore from backup
- Restore to factory settings/new iPod.
- Make an appointment at the Genius Bar of an Apple store.