Installed plugin as instructed. Immediately noticed only in IE7 that special characters were displaying garbled after being cached. For instance, bullets were being replace with garbled characters. I think apostrophe's were messed up also.
Tried just activating wp-cache without super cache through the plugin but the problem remained. So I uninstalled the entire plugin, reinstalled wp-cache after removing the special cache files and everything seems back to normal with no errant characters appearing. I wasn't sure of the exact procedure to uninstall (did nothing with htaccess files).
It did seem the html caching improved performance and I'd still like to use the plugin once this problem is eliminated.