This is a known issue only. This happens because, each button is from different sites (facebook, tweetmeme, digg etc) with different CSS, styles and positions, so this occurs naturally. Since WP Socializer deals with many buttons it not possible to concentrate only on certain combination to align them automatically with some generated CSS.
I am constantly working on this issue and looking for some alternative way to make this work good and effective.
You can use some CSS to align them. But please note that this is only the 1st version. You have more features and bugs solved in the forth coming versions