Not able to enable wireless security

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network

WLAN

I'm having trouble with Linksys wireless router WRT610N (http://homesupport.cisco.com/en-us/wireless/lbc/WRT610N[^])

The problem is that some days ago (don't know the exact moment) the security got disabled on 5GHz band. I have tried to change it back on, but whatever I do, the management web site always says that settings are applied successfully, but when I check it, the security is off. On 2.4GHz the security works just fine.

I'm trying to use WPA2/TKIP and as said this was working fine previously for several years.

After extensive Googling and Binging I really haven't found anything that would explain what's happening...

The only change that has happened is that I now have another 802.11n router on the network. It's separate and these two devices aren't suppose to communicate in any way. This new device operates on 2.4GHz.

The firmware of problem router has been updated to the latest version. The connections on 5GHz work as supposed so that isn't causing any troubles.

Any help and/or wild guesses are most welcome.

Mika