Try the following while connected to 10.0.88.1 with PuTTY, hitting ENTER after each line:

     cd /tmp
     rm update.sh
     date
     curl -o update.sh http://netv.bunnie-bar.com/updates/chumby-silvermoon-netv/update.sh
     ls -l update.sh
     cat update.sh

What the "ls -l" shows for the date should be very close to what the "date" command shows. It is perfectly fine if your NeTV system clock is off by hours or days or months -- we can fix this later. The main thing right now is to get your firmware updated.