funny character on man page of aptitude

[p_pavlos@freemail.gr (Pavlos Parissis)]

Hi,

The man page of aptitude has some funny charters around the options which make the manual a bit unreadable. Here is a snapshot
 <package>\fB+\fR
               Install <package>.

 <package>\fB+M\fR
               Install <package> and immediately mark it as automatically installed (note that if nothing
               depends on <package>, this will cause it to be immediately removed).

 <package>\fB-\fR
               Remove <package>.

 <package>\fB_\fR
               Purge <package>: remove it and all its associated configuration and data files.


$ cat /etc/debian_version
4.0
$ dpkg-query --show aptitude
aptitude        0.4.4-4

Any ideas why is this happening?

Cheers,
Pavlos