Editing / previewing / saving styles results in multiple asterisks next to Style Sheet name

After editing a Style Sheet for a while in one session (multiple edits / previews / saves), multiple asterisks appear before the Style Sheet name in the edit window.  There should be only one asterisk (only if the file has been modified and has not been saved since modification).

This bug makes it difficult to whether or not the currently open Style Sheet has been modified.
