I previously used Xionia recovery to create a second partition on my sdcard. The partition is ext3. Previously while running Lego ROM, I was able to run Link2SD which mounts it at boot time as /data/sdext2 and moves selected app, app cache and lib files to it. After switching to Reborn ROM v2, Link2SD can no longer mount the partition nor can I mount it manually in Terminal Emulator or using adb shell. I know Picastick's v7 kernel has support for ext2, ext3, and ext4, so this is basically a question for Nick7 if he knows of what difference between Lego and Reborn that might be the cause?
Further details: Link2SD mounts the script at boot with the same script in two places: /system/etc/install-recovery.sh and /system/etc/init.d/11link2sd. It was probably the init.d version that executed under Lego. The script contains the following:
#!/system/bin/sh
#added by link2sd
sleep 2
mount -t ext3 /dev/block/vold/179:2 /data/sdext2
mount -t ext3 /dev/block/mmcblk0p2 /data/sdext2