to answer the 1st post
sounds to me like you need to mess with the sleep option of the iPod.... menu> settings> sleep
the ipod does not turn on and off it actually puts itself into sleep and a deep sleep just as a computers hard drive would...
about sleep document:
http://docs.info.apple.com/article.html?artnum=60945
for the rest of you that are having trouble with your iPod being recognized by the computer.. try resetting the iPod while connected to the computer.. also if you have trouble resetting try putting it on a flat surface while pressing the combination to reset..
resetting iPod document:
http://docs.info.apple.com/article.html?artnum=60956
try this document and see how it helps if not reocgnized on computer still:
http://docs.info.apple.com/article.html?artnum=61711
for the last post... its really hard to say because it depends on what icon you are receiving
if you are receiving !folder icon
read this document:
http://docs.info.apple.com/article.html?artnum=61003
if you are receiving a sad face icon
read this document:
http://docs.info.apple.com/article.html?artnum=61771