hi all, i was able to upgrade successfully from leopard to snow leopard with a USB thumb drive when my internal HD died in my macbook pro a few weeks ago. i am now trying to upgrade my wife's macbook to snow leopard (from tiger) but i cannot get startup manager to recognize the drive! the bizarre thing is that the thumb drive is recognized just fine in finder (this includes disk utility and even system preferences) on her macbook. i can even double click the mac os x icon on the thumb drive and it will ask me to press restart to proceed with installation of snow leopard. however, after the computer restarts, it just loads right into the tiger os desktop. i've tried holding down the option key, resetting the PRAM, etc. nothing works. does anybody have any ideas? thanks very much in advance..