Strange WP-Supercache WordPress Folders

I use WP-Supercache, an amazing WordPress plugin which caches html pages of our php pages and reduces the server load drastically. But due to recent internal server errors, I looked inside my WordPress supercache folders and found some strange folders. As you see there were 3 folders, though quickonlinetips.com folder was expected, quickonlinetips.com. (with a period [...]