-On Recovery, start the adb daemon,
-On pc, open a command windows, open adb shell
type:
cd /dev/block
mknod mmcblk0 b 179 0
mknod mmcblk0p1 b 179 1
and there you go. You can now mount sdcard on recovery.
Ref:
http://wiki.cyanogenmod.com/wiki/Motorola_Defy:_FAQ