when I was trying Qt 5.2, querying a SQLITE3 db filtering on BOOL field gave me correct result:
QSqlQuery query;
query.prepare("SELECT * FROM myTable WHERE boolFilter = :filter");
query.bindValue(":filter", myFilterValue);

trying the same code using Qt 5.3rc query returns no record; trying this code it starts again to work:
query.bindValue(":filter", myFilterValue ? "true" : "false");

I think it was correct before version 5.3