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.
Actually, images are inline elements, so text-align: center; should be fine. If you have a line break above and below the image, it will be on its own line and go centered in the sidebar area.
Here is what I have got so far:
#sidebar {
clear:right;
float:left;
font-size:12px;
padding-left:15px;
text-align:left;
width:246px;
}
#sidebar img {
}
#sidebar img {margin: 0 auto;
}
Again the god of CSS design has done it.
Thanks Chris :P