Hi,
Try using a small brush, like a tooth brush, to remove any debris from the iPod touch or the dock.
Does the dock have the "Made for iPod" logo? If it doesn't, it might be trying to charge the iPod via firewire.
!http://devimages.apple.com/iphone/program/images/sdk_mfip.png!
+"iPhone 3G, iPhone 3GS, and iPod touch (2nd generation) do not support FireWire and will not charge from any FireWire-based power source. If you connect either of these devices to a FireWire-based charger or accessory"+
from
http://support.apple.com/kb/HT1476
-Jason