Will wireless configuration settings cache a WAP’s MAC address?

I had 5 identical Cisco WAP200 units situated throughout the office, each with the same SSID (we’ll call it “NED.”) A corner of the office had a weak signal, so I added a sixth WAP200, again with an SSID of “NED.” Over the last few weeks guests to the office in the same corner have continued to struggle with the wireless signal. Is it possible that their wireless client settings have cached the MAC address of the WAP200 that they connected to on a previous visit, and they’re automatically connecting to the WAP200 with the weaker signal rather than the new WAP that’s near them with the strong signal?