You will need to downgrade back to version 1.0 to downgradey simply re-install the cd that came with your iPod. If you don't have the cd or your cd came with update version 1.1 then follow these instructions....
Here are more detailed instructions on how to go back to 1.0, espescially if you bought your iPod in the last couple of months and it came with 1.1.
First, please download the older version of the iPod Updater here...
http://appldnld.m7z.net/content.info.apple.com/iPod/ww/win/061-2225.20051128.PDW nw/iPodSetup.exe
Now install that updater and restart your computer.
Now open the iPod updater (Start-->all programs-->iPod and find the iPod updater you just installed
Open the iPod Updater and connect your iPod. With that older version of the iPod updater you just installed, restore your iPod by clicking restore.
The iPod will restore and go back to software version 1.0. Now reload everything back into iTunes.
If you don't want to restore, see this...
http://discussions.apple.com/messageview.jspa?messageID=1813873