Depending on the current state of your A600GS / A1200NG system, you may see a two phase update, when it installs 1131 with the avcodec components.
The normal update will complete and the system meu will restart as normal, but then as long as you have AutoLogin enabled it will straight back into the advanced update panel and start installing AVCodec. This is quite a big update and may take a little longer than usual, please be patient and do not power off whilst it is updating.
Once complete, you will be able to continue without a further reboot.
