Thanks for the report.  The same problem appears in the 4.4 release.

Fonts have been somewhat broken for several releases and we really
need to fix them up some day.

On Thu, Feb 6, 2014 at 3:12 AM, Vaidotas Didžbalis <vaidasd at gmail.com> wrote:
> Hello,
>
> reported two bugs Version 4.5-13671:
>
> 0007809: turning off bigDisplay preference does not return to the
> previous display settings.
> 0007810: Cursor is positioned improperly for the underscore character
> '_'(asciiValue 95)
> Using default preferences paste the string
> '__________________________________' in workspace, and press End key.
> Cursor is positioned improperly for the underscore character
> '_'(asciiValue 95)Bitmap DejaVu Sans, all font sizes. .
>
> regards,
> Vaidotas
>