I cannot think of a different issue as this is the only 3g dongle that is use with the Mark V. I just know that if I roll the Mark V back to 1.0.4 the modeswitch takes place and issuing ls -l /dev/ttyUSB* results in /dev/ttyUSB0, /dev/ttyUSB1 and /dev/tty/USB2 being detected whereas rolling the Mark V forward to 1.1.0 or 1.1.1 and issuing ls -l /dev/ttyUSB* results in "No such file or directory." I shall continue to compare 1.0.4 with 1.1.1, but any help or advice would be much appreciated.