> Multiple access points should share the same SSID. They must have exactly the same security settings (same password, exact same mode, i.e. WPA2-PSK Personal) for clients to be able to automatically roam between APs.

I will also add to this, consider having all the APs on the same channel. My experience is that some OSs (I'm looking at you, Windows) don't roam properly if the following three things are not the same:

1. SSID

2. Authentication/Encryption

3. Channel

It does sound like the author has deployed consumer access points. For a proper office scenario centrally managed is the way to go. Finally, never use WPA2-PSK Personal in a work environment. Use proper back-end authentication such as Radius or MAC filtering, or a 'Register me via a captive portal' system with a central LDAP type user directory.