To reproduce the problem:
1. open an existing page for editing, page must be long enough for the scroll bar to be active
2. use the edit box scroll bar to scroll down toward the bottom of the page
3. click on the spot in the text where want to edit, which establishes the edit point
4. hit a character key to insert a character
When you insert the character the Edit Box scrolls up hiding the edit point and new character from view. If you enter another character the Edit Box scrolls back down, making the edit point visible again, but only for instant. It then scrolls back up immediately. Any key input has the same affect, even the up and down arrow keys. This only happens when using IE 8 and only when Compatibility View mode is not being used.
We initially got complaints about this problem from people who were working from home and had upgraded to IE 8. The same people had no problem editing with IE 8 when they were in the office. It turns out that by default IE 8 is configured to have Compatibility View mode enabled when viewing intranet sites. This is configured in the Compatibility View Settings dialog box, which can be opened by selecting Compatibility View Settings on the IE 8 Tools menu. When we disabled Compatibility View mode in IE 8 on the office machines we had the same editing problems people were reporting from home. Compatibility View mode makes IE 8 compatible with IE 7.
When this problem was initial reported we were running DokuWiki 2008-05-05 with DokuBook 2008-05-04. We just upgrade to DokuWiki 2009-02-14b and DokuBook 2009-02-08. We continue to have the IE 8 editing problem.