This might seem counter-intuitive, but you should figure out exact what causes it to "glitch".
Hold the iPod at each corner and try twisting it (gently but firmly) in different directions. If this causes it to glitch, it's probably physical damage or a loose connection inside of your iPod.
Try pressing on the iPod in different parts, such as the corner with the grey spot and all over. If any of these cause it to glitch, then something is loose or damaged.
Turn it off and on, reset your settings, mess with the wireless options, try playing games, and so forth. If it seems like any specific settings or games or things like that are causing it to glitch then you might try a backup and restore, and if that doesn't work then just a restore.
Hopefully that helps!