Both tuners on the Kworld do work for recording - you need to configure them separately though and ensure the services are mapped onto the same channels.
One thing I have noticed with mine is that the signal strength reported by the second tuner is lower than the first so you need to ensure a strong signal is provided.
Easy check - go to the DVB Input where the device name is shown as "Kworld UB499-2T T09(IT9137)*_1*" - click multiplexes and ensure they are all enabled, then on the "Services" tab check all the channels are enabled and mapped.
Now repeat the process for the second tuner "Kworld UB499-2T T09(IT9137)*_2*" - the Channel Name needs to be identical
Some more detailed instructions with scree-shots at
http://kjs1982.me.uk/article/kworlddual