Hi all!

I'm having intermittent i2c dropouts between a new Verdex Pro XM4 and
Robostix with a Netpro-vx.  I have a 24-pin flex cable to a USB adapter too,
but the SDA and SCL pins on the 24-pin are left floating.

I can flash programs to the Robostix just fine, such as the i2c-bootloader.  But then
when I try to load a program over i2c, it fails many times before it finally gets it right:

~~~~~~BEGIN CONSOLE OUTPUT~~~~~~~~~
root@gumstix-custom-verdex:~$ ./robo-load.sh Robostix/i2c-io.hex
Beginning i2c-load of Robostix/i2c-io.hex...
Detected ATMega128
Write:  #ERROR: I2cTransfer: ioctl failed: Connection refused (111)
ERROR: BootLoaderWrite: I2cWriteBlock failed: Connection refused (111)

ERROR: Error writing 28 bytes to 0x21c
i2c-load ended.
root@gumstix-custom-verdex:~$
root@gumstix-custom-verdex:~$ ./robo-load.sh Robostix/i2c-io.hex
Beginning i2c-load of Robostix/i2c-io.hex...
Detected ATMega128
Write:  ##ERROR: I2cTransfer: ioctl failed: Connection refused (111)
ERROR: BootLoaderWrite: I2cWriteBlock failed: Connection refused (111)

ERROR: Error writing 28 bytes to 0x400
i2c-load ended.
root@gumstix-custom-verdex:~$ ./robo-load.sh Robostix/i2c-io.hex
Beginning i2c-load of Robostix/i2c-io.hex...
Detected ATMega128
Write:  ##ERROR: I2cTransfer: ioctl failed: Connection refused (111)
ERROR: BootLoaderWrite: I2cWriteBlock failed: Connection refused (111)

ERROR: Error writing 28 bytes to 0x400
i2c-load ended.
root@gumstix-custom-verdex:~$ ./robo-load.sh Robostix/i2c-io.hex
Beginning i2c-load of Robostix/i2c-io.hex...
Detected ATMega128
Write:  #ERROR: I2cTransfer: ioctl failed: Connection refused (111)
ERROR: BootLoaderWrite: I2cWriteBlock failed: Connection refused (111)

ERROR: Error writing 28 bytes to 0x154
i2c-load ended.
root@gumstix-custom-verdex:~$ ./robo-load.sh Robostix/i2c-io.hex
Beginning i2c-load of Robostix/i2c-io.hex...
Detected ATMega128
Write:  ##ERROR: I2cTransfer: ioctl failed: Connection refused (111)
ERROR: BootLoaderWrite: I2cWriteBlock failed: Connection refused (111)

ERROR: Error writing 28 bytes to 0x400
i2c-load ended.
root@gumstix-custom-verdex:~$ ./robo-load.sh Robostix/i2c-io.hex
Beginning i2c-load of Robostix/i2c-io.hex...
Detected ATMega128
Write:  #ERROR: I2cTransfer: ioctl failed: Connection refused (111)
ERROR: BootLoaderWrite: I2cWriteBlock failed: Connection refused (111)

ERROR: Error writing 28 bytes to 0x154
i2c-load ended.
root@gumstix-custom-verdex:~$ ./robo-load.sh Robostix/i2c-io.hex
Beginning i2c-load of Robostix/i2c-io.hex...
Detected ATMega128
Write:  ##
Verify: ##
Verify sucessful
Write sucessful, rebooting...
i2c-load ended.
~~~~~~END CONSOLE OUTPUT~~~~~~~~~

I get a similar thing from i2c-io.  It almost always repeats as failed,
succeeded, failed, succeeded for i2c-io, while i2c-load fails many times
before succeeding.

~~~~~~BEGIN CONSOLE OUTPUT~~~~~~~~~
root@gumstix-custom-verdex:~$ i2c-io 0x0b info                 
ERROR: I2cTransfer: ioctl failed: Connection refused (111)
ERROR: I2cReadBlock failed
ERROR: Unable to retrieve information from i2c address 0x0b
root@gumstix-custom-verdex:~$ i2c-io 0x0b info
    version: 2
  minVersion: 1
SVN Revision: 22
~~~~~~END CONSOLE OUTPUT~~~~~~~~~

I can get around this by using the serial interface between the gumstix and robostix
in the short-term, but this is really important in the long term because I have a
magnetometer that I need to talk to over i2c, so I need to figure out what's up with
my i2c bus.  The i2c-test utilities work just fine, and I think my power supply is fairly
clean (putting ceramic caps on the power didn't change anything).

Thanks!
-Ned