I can only upload a sketch to my Arduino Pro Mini once

Hi all,
I recently received two arduino pro minis from amazon. (Link) They seemed to work fine when i plugged them in with my CP2102 USB to UART adapter (Link). I uploaded a sketch fine, but when i try to upload a second sketch this is what i get:

avrdude: Version 6.0.1, compiled on Apr 15 2015 at 19:59:58
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2009 Joerg Wunsch

System wide configuration file is "C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf"

Using Port : COM5
Using Programmer : stk500v1
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x03

avrdude done. Thank you.

Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

The bootloader is still on the board as when i reset the board the on-board LED blinks. I have read that there are some reset issues with the USB converter, but i have held down the reset button when it uploads but still the error occurs. Just to emphasize - it did work the first time, which befuddles me.

(I love the word befuddles)

Thanks for any help you can offer
August

EDIT I ordered two pro minis and this happened on both of them.

thauke:

         Using Programmer              : stk500v1

This implies you've selected the wrong board in the board menu.

I definitely have the correct board selected as the only thing I changed after the first upload was one line of code to add an extra blink in the blink example program. I am positive that it is on Arduino Pro Mini with Atmega328-5v and 16mHz.

thauke:
I definitely have the correct board selected

Well either you don't, or your installation has been corrupted.

Seems strange such a specific error would be introduced by any kind of corruption.

The programmer type being used, is wrong for a Pro Mini. It is defined by the boards.txt file.

So i have restarted my laptop and now the programmer line reads:

Using Programmer              : arduino

But the error still occurs - everything else is the same.

Turns out it was a reset problem - my USB - UART converter doesnt have a dtr pin, so i needed to manually solder it from the chip itself.
Thanks for all your help
August