IE6/Win: Keyboard shortcut for bold text stops working after inserting bulleted list

Using Internet Explorer 6 on Windows, do the following steps:

1. Open something that triggers HTML area editor.
2. Type some text. Select some text, make it bold by pressing Ctrl-B.
3. Type some more text. Make some of it into a bulleted item list by clicking the button in the HTMLarea toolbar
4. Type more text. Select some text, press Ctrl-B.

Expected result: Text becomes bold.

Actual result: IE6 bookmarks dialog appears.