Cleanup the imported parameters
Sometimes there's a random string in the free text parameter, f.e. in http://www.katalogrouteru.cz/review/asus-rt-ac66u-rev-a1-firmware-3004140-2013-02-18/ the value of "OS podporované v admin aplikaci" is "na". I've also seen "No".
Please dump all non-boolean parameters from the database and do the cleanup.