What is your clickthrough rate (percentage), and how much on average are you making per click? These are important measures to really judge 'how you are doing' in terms of AdSense, and whether there is a problem at all. It is possible that your keywords don't have a high CPC, and that you can't do much better without tweaking your content.

One thing I do notice though is that you allow banner images and text; studies have shown that people are more likely to click on text ads than banner ads, so I would change that in your AdSense settings to only allow text ads.

Well the most important part is what kind of visitors you have for your blog. You should try and find out what are the interests of your visitors. Selecting a proper channel in the adsense and displaying the proper ads at the right time when a visitor is viewing your blog will get you more clicks.

I'm in the same boat as you as far as visitors go. I get a max of about 200 per day total but I make $1-4 a day with adsense clicks. My CTR is about 5-10% and I use the horizontal ad block. (480?x90) I'm unsure of measurements. I place my block right below my H1 tag so if someone isn't thinking, they might click thinking it's part of my site. It sounds shady but if you saw my site then you wouldn't think so. I also set certain ads to not be displayed when I don't think my visitors are gonna click on them.

Don't know if any of this helps but that's my current situation.