All, I seem to be seeing some funny behaviour with PTT express on MC40s and was wondering whether anyone else had seem similar. 1) If the MC40s are left to support both 2.4GHz and 5GHz wireless bands (i.e. the default) then devices that connect to a radio on one band will not communicate to MC40s on the other band. This is despite the fact that the same WLAN is being transmitted, with the same security, on the same subnet on both frequency bands. 2) We are also seeing instances (albeit in a lab not in a live environment) where you make a PTT call on one device and it is received on all the other devices, then after a period of time you try to make a new PTT call and it is received on NONE of the other devices. It doesn't matter which one you choose or how long you wait (we have waited 10+ minutes and it still will not work). If you then reboot ONE device (doesn't matter which one), or just disable and re-enable the WiFi on one device, then everything starts working again. Has anyone seen anything similar or could offer any guidance? Thanks IJ