Or maybe your page is not optmized for adsense, and with many ads it was more easy to show ads with no related content to your pages/ I am wondering about this. Test for just a couple of days maybe doesn't give trust
Nope my page is very optimized for adsense, there are many articles on the less ad more money theory, but it does seem to work that way for me, I've restrict my pages to two ads per page.
Yes, definitely, less is more. By putting less ads, the advertisements will be concentrated and clicks more valuable.