Hmm. Which superuser app did it install? It's not uncommon to need to either update the superuser app and / or update the SU binary (should prompt through the app if needed). Go to the Play Store and see if there is an update to the app, then open it and see if it prompts you to update the binary as well. If you don't have the Play Store on your device, just let me know which version of the SU app was installed and I'll see if there's is an update available. I don't get the chance to mess with many off brand products like this, so do not have direct experience, just tons of android experience in general.
Found some more info from a random Russian site (via Google Translator) http://translate.google.com/translat...%26es_sm%3D122
Might try and install CWM recovery and flashing Chainfire's SuperSU zip if all else fails.
Need some help, advice, something fixed? Hit me up on Hangouts @ es0tericcha0s
Now offering unlocking services - including many Sprint phone unlocks! PM for details!
HTC Droid Eris / Motorola Droid / Samsung Galaxy S Fascinate / Motorola Droid X / LG G2x / HTC Evo 3D (x2) / Samsung Epic 4G Touch (Sprint S2) / HTC Amaze / Samsung Galaxy S3 (International) / Samsung Galaxy Note 2 / Nexus 4 / HTC One / Samsung Galaxy S4 / Sony Xperia ZL / Nexus 5 / OnePlus One (64 GB)