atmega32u4-aur based board. shows as COM port but cant program???

hi,

ive made a board based on the arduino micro schematic, and flashed using the Caterina-Micro.hex bootloader. I have made two boards off the same schematic. Im using Atmel-Studio.

The first board once i set the fuses worked fine, fully recognised USB Serial COM port, and also accepts uploads using the Arduino IDE.

The second board also shows up as a USB Serial port in device manager, and if i do a hold reset down and release once the Arduino IDE is looking for the COM port it finds the COM port but cant find the programmer.

any tips??

should i try a different boot loader??

[quote]Sketch uses 4,594 bytes (16%) of program storage space. Maximum is 28,672 bytes.
Global variables use 149 bytes (5%) of dynamic memory, leaving 2,411 bytes for local variables. Maximum is 2,560 bytes.
PORTS {} / {} => {}
PORTS {} / {} => {}
PORTS {} / {} => {}
PORTS {} / {} => {}
PORTS {} / {} => {}
PORTS {} / {} => {}
PORTS {} / {} => {}
PORTS {} / {COM10, } => {COM10, }
Found upload port: COM10
C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avrdude -CC:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf -v -patmega32u4 -cavr109 -PCOM10 -b57600 -D -Uflash:w:C:\Users\chendy\AppData\Local\Temp\build9c9ef3bdfe2fccb480bc6e4bac749e41.tmp/Blink.ino.hex:i 

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                    : COM10
         Using Programmer              : avr109
         Overriding Baud Rate          : 57600
         AVR Part                      : ATmega32U4
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PA0
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    20     4    0 no       1024    4      0  9000  9000 0x00 0x00
           flash         65     6   128    0 yes     32768  128    256  4500  4500 0x00 0x00
           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           lock           0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : butterfly
         Description     : Atmel AppNote AVR109 Boot Loader

Connecting to programmer: .avrdude: butterfly_recv(): programmer is not responding
Problem uploading to board.  See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.[/quote]