We report on the non-detection of radio emissions indicative of Titan lightning by the Cassini RPWS (Radio and Plasma Wave Science) instrument. A previous study by Fischer et al. (2007) investigated the first 35 Titan flybys, and here we continue our search until the end of Cassini's equinox mission. No bursts that would clearly indicate the existence of Titan lightning were found. Great care is needed in the interpretation of bursty signals since spacecraft interferences, Jovian decametric arcs, solar radio emissions, and enhanced background fluctuations can sometimes mimic lightning bursts. During several Titan flybys the strong radio emissions of Saturn lightning were detected which can be distinguished from potential Titan lightning since they don't fall off in intensity with increasing distance to Titan. We show an example of an occultation of the Saturn lightning radio source by Titan.