Comment 18 for bug 273336

I have the same problem as described by the original poster.

In nm-connection editor, create a new network

Connection name: Wireless connection 1

Wireless tab:
SSID: Q9PDANE813
Mode: Infrastructure

Wireless security tab:
Security: WPA & WPA2 Personal
Password: A12B34C56D78E90F12

OK.

Close connection editor. Open it again.

Password has changed to a long string starting: 5e470696...

Open Seahorse, Passwords tab.

Network secret for Wireless connection 1/802-11-wireless-security/psk
Properties, show password.

It has the same long string starting: 5e470696...

Interesting that this is the same string obtained by

$ wpa_passphrase Q9PDANE813 A12B34C56D78E90F12
        network={
        ssid="Q9PDANE813"
        #psk="A12B34C56D78E90F12"
psk=5e470696...snip
}

So, nm-connection editor is storing the wrong thing in the keyring.