There is a bug in the August 2014 TRF-2400 and TRF-2460 firmware that causes the output to be stuck on 576i and possibly the yellow function key to stop working. If you use component (or composite) output rather than HDMI the picture is 'stuffed'. The procedure for fixing this problem is provided on the Topfiled Australia www site: http://topfield.forumchitchat.com/post/output-stuck-on-576i-after-firmware-update-a-solution-7200422?pid=1285343901#post1285343901
Other things can also go wrong and the procedure described appears to fix them.
The 'bug' appears to be in all firmware for Australian Toppies releases since March 2014.
Ian