The TZT2 and TZT should not be mixed with a different series of software. When the v6 software of the TZT2 was released, this was posted under the Furuno news topic area. That is most likely what you talked about seeing. Those with mixed systems should wait to upgrade the TZT2 to v6 until they also have TZT v6. We hope to have an early release of V6 for TZT in a few weeks. Right now Japan is on holidays with Golden week.