Some tech feedback, browsers, adverts, contact page

Hello TF Techies and Great work on this nice site!

Just FYI:

Adverts do not show up when using "Opera" or "Mozilla Firefox" browsers.

"Android" cell phone displays adverts (although very tiny).

Thanks and keep up the fantastic work!

also: I attempted to send this via this site's contact page to technical, however the "Captcha" question/answer windows are not visible - hence could not complete the contact (i tried it 3 times - no joy).