Im having the wierdest problem...mind boggling. For weeks my site has been dropping off and on google every couple days. I noticed that if I hit preferenced on google and turn the filter on so its filters all adult content....my site will return to google and rank GREAT! If I turn all filters off....my site dissappears from google. If I had adult content, this would be the exact opposite? I do have a lot of girl wallpapers but no nudies that Im aware of. This only happens on my homepage. epicwallpaper.com
Your 'girl wallpapers' are borderline adult content. Most parents probably wouldn't want their kids looking at those images. Also you link to some websites that have nudity. It is strange that your website only shows up when the filter is on. I haven't heard of that problem before. When I search for 'epic wallpaper' your tag cloud page shows up on the first page. Perhaps there is some problem causing that page to compete with your homepage. Maybe try getting a bunch more links to your homepage.
I thought google was confusing other pages as my homepage as well... but my homepage is PR4 and anything else is PR3. My homepage also has thousands of backlinks from high PR sites.