How often do you collapse your subscription list in your Google Reader? I assume you tried it once and after that you never did it again. So why not remove it? It’s simpler you think:

1. Go to your Firefox profile/chrome/ directory.
2. If there’s a file called usercontent.css open it, otherwise create a new file with that name.
3. Enter the following:
   #chrome-lhn-toggle {
display:none;
}

4. Restart Firefox.
5. Enjoy!