this is just a guess, and I could be completely wrong (it’s all trial and error for me, so I’m still learning what works and what doesn’t); but try this:
What has worked for me with aligning images especially in the sidebar has been setting it as the background-image. This maybe a newbie move being I just completed my first CSS site. I just seem to have better flexibility when I do it this way. The text seems to play better as well.