Hmmm...I've looked in two different versions of ClockworkMod recovery source at the nandroid.c code. Both basically ended-up invoking the
mkyaffs2image funciton (see the source here:
/var/www/vhosts/netmite.com/android/mydroid/external/yaffs2/yaffs2/utils/mkyaffs2image.c).
The mkyaffs2image function will basically (from what I can tell) return a error code of 1 in just about any circumstance that can produce an error (not enough free space, write error, invalid directory, improper formatted filesystem, etc.).
I believe that ClockworkMod creates a
/cache/recovery/log file containing a transcript of session and error messages that would get produced, but you'd probably have to use the Android SDK's
adb utility to shell into your DX while recovery is still running to retreive the log file ("
adb shell pull /cache/recovery/log cwm-recovery-log.txt" for example) to really identify the exact error or possible cause.
I supposed you could try using a different (newly formatted and empty would be best) SD card to really eliminate and isolate the possible causes.
Hope this helps.
Cheers!