I've been using a rather old AirPort Express for home Wi-Fi for a number of years. (It's old enough that it only supports WPA, not WPA2 -- perhaps this is an indication that I should upgrade!)

In the last week I've been experiencing very slow internet over the Wi-Fi. Suspecting that someone outside my home was leeching from me (despite a reasonable password and MAC address filtering turned on) I decided to change some settings: I changed the SSID, turned off broadcast of the SSID and changed the password.

After these changes, I managed to connect using the new password on my iPad. But on the other devices I tried (iPhone, PS3) I was not able to connect. In fact, I only succeeded in connecting when I entered my OLD password!

Is this a known issue with ancient AirPort Express units? Is my unit cracked and unrecoverable?