Left-hand text vanishes in IE7 when editing right aligned im

I've found a strange problem when editing in IE7 using FCKEditor 2.4.3 build 15657. After saving content that has text to the left of a right-aligned image, the majority of the text immediately to the left of the image disappears. It looks like this:



As soon as the mouse pointer is moved over an FCKEditor icon that pops up a tooltip, or the mouse pointer is moved over the edit area, the text re-appears, and looks like it should -- like this:



This problem does not occur in Firefox.

Any clues as to why this might be, or better yet, a way to fix it?