Wrapping Text Around Images with some themes

I have a new WP 2.7 blog and I put an image and wanted to wrap text around it. In the editor, I set the alignment left and the text wraps fine. However, when I view my blog, the text is not wrapped.

I went to the page http://codex.wordpress.org/Wrapping_Text_Around_Images and the text is not wrapped around the images there! That really got me confused.

I tried what that page saya, adding the required entries to style.css for my theme, but that didn’t help. (Similar entries were already there).

I have found a few rare themes where the text wraps, but most don’t. The WP Default theme worked, but the WP Classic one didn’t.