Metasploit Host List

Why is it that Metasploit dosent add all hosts to the database from an Nmap scan?

I did an Nmap scan within Metasploit as so:

"msf> db nmap -sS 192.168.5.1/24" to find all host on my home network.

Nmap finds 6 hosts (IP addresses, MAC addresses), but dosent copy all of the info into the database.

When I do command like "msf> hosts" it just lists 3 hosts (IP add and MAC add).

Same thing when i try to do a Nmap scan and import it into Metasploit via "msf>db import nmap-scan-file-name" command.

From what i can tell, Metasploit only copy's the routers info and the Windows machines info, and fales to copy the rest.

Any ideas?

Peace, Alpha