I've been using a Linksys Wireless-G 2.4ghz router for a pretty long time now.. with relatively no problems.

Today I could not find my SSID! I reset the router - still no luck, so I plugd in via ethernet to check the transmission and status. Well my SSID has changed from linksys_XXX to linksys_SES_XXXX where x=numbers... also my password has changed to a TKIP+AES, WPA pre shared key.

Why would this happen?? This is not due to a router reset. I have reset this router in the past, at which point the password protection is turned off entirely and SSID is broadcast as "linksys".