Please Help: Very Slow Wifi on ipod touch 2g

I updated to 3.1.2 on my ipod touch 2g from 2.2.1, and since i updated my average wifi speed has gone from 2 to 3mb/sec to less than 500kb/sec. It takes forever to play even a 1 minute youtube video

I tried resetting the network settings and even a full restore, but nothing has worked

any suggestions to fix this?