Why restart Matlab after USB Serial port has been disconnected?

I am using the serial port of may computer to communicate between a microcontrolles and matlab via USB-Serial UART-chip (FTDI). This works fine when i connect the microcontroller before I start matlab. When I first start matlab and then connect the microcontroller, It wont' work (or I cannot make it work). The problem ist that when programming the microcontroller, I have to disconnect it from the computer. This way I have to stop and start matlab all the time during these programming sessions. Would there be a way around this problem, i.e. will matlab find this serial connection once the cable is unplugged and then re-inserted again?

Thanks for any help, Kai Boetzel