I have an Arduino Nano v3, up to this point i had no issues with it. today i loaded a program on it, that dumps sensor data to the pc on the serial monitor. I have done this many times before, but now it is "stuck in serial transmit mode". Any time I try to upload a new sketch my device does the usual reset procedure before upload, starts the upload, but after 2 brief blinks of the Rx led the Tx lights up and stays on (Very quick blinking), ando nothing else happens. If left untouched, PC says uploading sketch and that is all. If I close the arduino IDE the controller keeps on transmitting (Tx led on) until I reset it with the reset button. If I start the serial monitor as usually it starts transmitting and stops when i close it. I tried every possible thing I could find on the forums, from different resets, to complete driver/ IDE reinstall, usualy I use windows 7 64bit, but I also tried Ubuntu, where despite of carefully setting up everything if I try to upload a sketch I get an out of sync error, but the controller is not stuck in this Tx loop.
Any idea or suggestion would be highly appreciated.