I think I have a problem with my switch

I have an Asus Switch with management and when I installed it all ports had 100 Mbps full duplex and then 2 ports started to have 10 Mbps full duplex and today my 3rd port is this way so I`m very newbie is this stuff and I would like to ask you if this thing is normal or I have to do something from the management software...if it matters the switch is Asus GigaX 1024 I.

a friend of mine told me that maybe that 10 mbps port are from computers with old network adapters....but I don`t know

if it matters one port of the Asus switch is connected with other switch with no management from Edimax but the rest of the computers are connected direct in the switch.....

Thanx and I`m waiting for an answer..

yes it was at 100 mbps but I`ve noticed right now, when the computer is shut down the switch indicates 10 mbps and when i turn on it is 100, seems odd but I think is some sort of thing at nvidia network adapters, but thx for responding..