Frederick,
I had similar issues when I installed w3tc. I ended up with the horribly frightening white screen of death where my admin panel should have been. I used Jared Hienrich’s post: How to troubleshoot WordPress “White Screen” of Death to recover. I also had to reload several times and remove files as prompted by missing file messages that came on the browser window.
I still have some of the w3tc files installed, but my site finally came back. I have not yet tried to reinstall the plugin, but I very much want to. I will remove all plugins to an temporary folder and leave “plugins” empty and try again.
Then I will reinstall each plugin, one by one until I find out which of them is the evil culprit.
Will let you know.
