Arduino UNO - can't upload

Using Arduino IDE 1.x
1

Hi,

Im having a problem with my arduino uno on Mac OS.
I tried to chmod folders /var/lock and /var/spool, tried to install drives and yet nothing seems to work our.

if i run it with 1.0.5 version first after restart i get error: avrdude: stk500_recv(): programmer is not responding,
other times i get: processing.app.SerialException: Serial port '/dev/tty.usbmodemfa131' already in use. Try quiting any programs that may be using it.

if im running on version 1.5.4 i get error: avrdude: ser_open(): can't open device "/dev/tty.usbmodemfa131": Resource busy

interesting thing is that only if im in first usb its visible in Serial Ports, when im in second one its not.
i tried to check if no one is using port by lsof | grep usbmodem command and it returned empty.

when i connected it to other laptop which runs on window it worked :fearful:

i have been searching for answer for two days and yet nothing seem to work out, have one idea what to try next :sleeping:

2

it seams that when i installed PL2303 drivers from here: Mac's and serial TTY's my mac was available to see both usb ports but now i have other problem i always get

avrdude: stk500_recv(): programmer is not responding

when uploading the TX and RX lights start blinking green and then L light lights red again and i get this message, any ideas?