When trying to mount an ext3 with "sudo mount_ext2 /dev/disk0s5 /test" it results in:
"mount_ext2: canceled automount on /dev/disk0s5 on /test: Operation canceled"
Any ideas ?
You've turned automount off in the prefs. Unfortunately, there's a bug in d1 and d2 that prevents turning it back on with the pref pane. So you can either delete the prefs file (/Library/Preferences/net.sourceforge.ext2fsx.ExtFSManager.plist) or pass '-x' to mount_ext2 to have the pref be ignored.