It seems so....., and try putting textual, one link ads on bottom side instead of banners. I use this proxy http:// www. born2hide.com/ because jus' one ad So your visitors might increase if you do so
In my opinion if you exceed 3 ads on a page then you have too many ads and you have not done that so I think it's fine.
I've seen worse that that because there are other proxy sites that even utilizes all 3 ad units + link units. Yours should be ok I guess without appearing to be annoying.