Well, after downloading the firmware you suggested, I tried to root it but no luck :-( The system is encrypted cramfs and until now for this firmware and chipset(rockchip 2918) there is no rooting.
After updating the firmware I went to system info to see if there was any change. Well,no! The firmware version is exactly the same as the previous one(v.1.28_0707). But there were same changes: I can now change the resolutuion to 1080p like your box bthoven! Also I can set the display output to VGA or TV(which my box hasn't! No VGA or composite output, only component) Apart from this I didn't notice any other changes in the system. If I find anything else I'll inform the forum here.