I have an interesting problem that has been popping up over the last several months. I am presently using a MSP-EXP430G22553 Rev 1.5. I am running Energia 17. Every so often when I load a program into the editor, the serial port option on the tools menu will be grayed out. I am able to download the program into the board and the program will run but I am unable to open the serial port window. I am running Windows 7 and if I look at the ports in device manager, it show port 66 being assigned to the TI board. This problem will continue for several days and then suddenly it will start to wor