I opened a site recently, and added some adsense. As soon as I look at my page, I see my leaderboard ad about air filters, a banner image ad about air filters, and my banner at the bottom about guess what? Air filters. My site is not about air filters, I noticed I put the word "filter" in my text for the welcome box about website filters for school and work. I rewrote my text to NOT include the word "filter", I took my ads off, went and got more ads, came back, and its still filled with air filter ads. Whats the deal?
I have heard similar reports of other website owners when they first started placing Adsense on their site. It sometimes takes some time before Adsense is serving the correct ads. You could try to move the progress along by using good page titles, meta tags, h1 tags etc.
Well, is it because your website is about proxies? I believe filters and proxies fall into the same category.
I was viewing a site once (an article site I think) and all the ad units were about golf and I wondered why it was picking that up when the site was absolutely nothing to do with golf. It was only one page that I viewed, so I don't know what other sections were showing.