[Plugin: WP Super Cache] Multi-Site: Caching sites where plugin's disabled

While using the WP Super Cache plug-in, I’ve found that it seems to activate itself on the entire multi-site network, even when you only enable it for specific sites within that network.

== WP Super Cache Version ==
0.9.9.6

== WordPress Version ==
3.0.1

== Steps to Reproduce Error ==

1. Install WP Super Cache on a WordPress multi-site installation
2. Activate the plug-in for a single site within the multi-site installation
3. Go to the backend of a site within the multi-site network on which you have not enabled the plug-in.
4. Modify a page or post in that site
5. Visit the page with your browser and view the source of the page

== Description of Error ==
At the very bottom of the page source, you will see something similar to:

`<!– Dynamic page generated in 1.044 seconds. –>
<!– Cached page generated by WP-Super-Cache on 2010-11-15 12:14:00 –>`

== Current Solution ==
In order to stop the pages from being cached by the WP Super Cache plug-in, I have to activate the plug-in on that site, then disable it within its “Settings” page.