I have only experienced this issue with the new version of the forums.
It only occurs rarely, and I have not determined any magic sequence.
When making forum posts, it is very typical that I will change the color of some selected text so as to emphasize it, and draw attention to it, within a larger provided context. After I have selected the desired text area, I move the cursor over to the "Text Color" button and then "click" to change the color (or open the pull down menu to select the color, if it is my first change). Sometimes (rarely) the text that changes color is not exaxtly what I have selected. Sometimes the first two characters do not change color. Other times the entire selection moves over two characters. If I try to go back and change the unchanged characters they never will change, the change always move right two characters. In the example of the attached screen shots, I was able to finally get the desired characters to change by selecting an extra few characters to the left also, and then changing them back afterwards. Also in this example, the added two characters at the right were the "[" and "\" of a closing code tag, which then messed up the code tags, which I figured out during "Preview Post".
This is better described by screen shots: First, text selected and cursor hovering over the "text color" button (cursor does not appear in screen shots); Second, the cursor is still hovering over the "text color" box, but after I have "clicked", notice the highlight has shifted two characters to the right; Third I moved the cursor to somewhere over a clear area in the text box and "clicked" so as to remove the highlighting, notice the text that turned red is not what I originally wanted; Fourth, is just from when I was trying to include extra characters so as to get what I really wanted.
ex_01.png ex_02.png ex_03.png ex_04.png
If, I can find them again, I'll come back and edit this post with links to other examples.
I tend to only use ubuntu server editions, so this type of work is done via a windows vista computer with IE version 9.0.8112.16421
Edit: Add Links to other examples:
http://ubuntuforums.org/showthread.p...3#post12566433 <<< Really good example, because other almost identical lines worked fine.