I recently got my hands on a pair of R300 AP's. I have upgraded these with the software version Release 184.108.40.206.1347 (Solo AP) to configure them as solo AP's.
I tried to configure a 2.4 GHz AP with WPA2 PSK AES encryption but my connection with the AP then resets and nothing is changed. I can activate an 2.4 GHz AP with the encryption method set to disabled.
So I guess I missed a setting somewhere, any thoughts?
Check what error you get in the log. If still not clear reason, reload the firmware. And I don't see any reason why to use standalone firmware, if you can use Unleashed, as standalone is very basic, so try it. Also check if you have a country setting set.