rkhunter --propupd option

[Paul Cartwright <ale@pcartwright.com>]

I run rkhunter, and I am getting this message in an email:
Warning: The O/S name or version has changed since the last run:
         Old O/S value: Debian lenny/sid    New value: Debian 5.0
         Because of the change(s) the file properties checks may give some 
false-positive results.
         You may need to re-run rkhunter with the '--propupd' option.

yet, when I try that, it says invalid option:
rkhunter --propupd
Fatal: Invalid option --propupd
paulandcilla:/etc# man rkhunter
paulandcilla:/etc# rkhunter -c --propupd
Fatal: Invalid option --propupd


what am I doing wrong??

-- 
Paul Cartwright
Registered Linux user # 367800
Registered Ubuntu User #12459