Seems like your guess is correct. Within the original u-boot image I see
ethact=egiga0
ethaddr=00:22:02:00:1e:ba
eth1addr=00:22:02:00:1e:bb
but not in the new one. For completeness, I post the full output of printvar for both images
###Good image (3G version from Excito)
B3> printenv
bootdelay=1
baudrate=115200
preboot=
loadaddr=0x800000
console=ttyS0
bootfile=uImage
flashfile=u-boot.kwb
installfile=install.itb
setdiskargs=setenv bootargs root=$diskdev console=$console,$baudrate serial=${serial#} key=$key button=$button
setbootargs=setenv bootargs root=$rootdev rw console=$console,$baudrate $othbootargs
usbbootroot=/dev/sda1
usbbootdev=usb 0:1
usbboot=usb start; setenv diskdev $usbbootroot; run setdiskargs; ext2load $usbbootdev $loadaddr /boot/$bootfile; bootm
usbflashdev=usb 0:1
usbflash=fatload $usbflashdev $loadaddr /install/$flashfile && sf probe 0:0 && sf erase 0 80000; sf write $loadaddr 0 $filesize
satadev=sata 0:1
sataroot=/dev/sda1
sataboot=setenv diskdev $sataroot; run setdiskargs; ext2load $satadev $loadaddr /boot/$bootfile; bootm
usbinstallroot=/dev/ram0
usbinstalldev=usb 0:1
usbinstall=usb start; setenv diskdev $usbinstallroot; run setdiskargs; fatload $usbinstalldev $loadaddr /install/$installfile; bootm
bootalt1=run sataboot || reset
bootalt2=run usbinstall || run usbflash || run sataboot || reset
ethact=egiga0
ethaddr=00:22:02:00:1e:ba
eth1addr=00:22:02:00:1e:bb
serial#=4773
key=MY9lUnZnipL/8TwjF/qU/X3Gzoc=
usb_custom_params=loglevel=8
netconsole=6666@192.168.2.101/eth0,6666@192.168.2.103/3c:07:54:49:20:cc
stdin=serial
stdout=serial
stderr=serial
button=0
bootcmd=run sataboot || reset
Environment size: 1343/65532 bytes
###
###New version w/o network interfaces as posted by moonman
B3> printenv
baudrate=115200
bootalt1=run sataboot || reset
bootalt2=run usbinstall || run usbflash || run sataboot || reset
bootcmd=run sataboot || reset
bootdelay=1
bootfile=uImage
button=0
console=ttyS0
eth1addr=00:22:02:00:1e:bb
ethact=egiga0
ethaddr=00:22:02:00:1e:ba
flashfile=u-boot.kwb
installfile=install.itb
key=MY9lUnZnipL/8TwjF/qU/X3Gzoc=
loadaddr=0x800000
sataboot=setenv diskdev $sataroot; run setdiskargs; ext2load $satadev $loadaddr /boot/$bootfile; bootm
satadev=sata 0:1
sataroot=/dev/sda1
serial#=4773
setbootargs=setenv bootargs root=$rootdev rw console=$console,$baudrate $othbootargs
setdiskargs=setenv bootargs root=$diskdev console=$console,$baudrate serial=${serial#} key=$key button=$button
stderr=serial
stdin=serial
stdout=serial
usb_custom_params=loglevel=8
netconsole=6666@192.168.2.101/eth0,6666@192.168.2.103/3c:07:54:49:20:cc
usbboot=usb start; setenv diskdev $usbbootroot; run setdiskargs; ext2load $usbbootdev $loadaddr /boot/$bootfile; bootm
usbbootdev=usb 0:1
usbbootroot=/dev/sda1
usbflash=fatload $usbflashdev $loadaddr /install/$flashfile && sf probe 0:0 && sf erase 0 80000; sf write $loadaddr 0 $filesize
usbflashdev=usb 0:1
usbinstall=usb start; setenv diskdev $usbinstallroot; run setdiskargs; fatload $usbinstalldev $loadaddr /install/$installfile; bootm
usbinstalldev=usb 0:1
usbinstallroot=/dev/ram0
Environment size: 1401/65532 bytes
###