Expand File System script does not work on Rpi 3 Beta version

Hi there.

I’ve been trying to install the Beta version on Rpi3 (the one available for download Jessie 2.28) and I have realized that after I do a file system expansion, I am left with a terrible mess.
The script runs without error messages in the web GUI BUT :

–> The second partition is not actually extended !!

New partition 3 is created nonetheless
Worst of all, I am left with a double entry in my mounts to / which is NOT cool at all ! (one in mtab, one in fstab).? Ihaven’t been able to correct this.

I have a complete mess inside my /etc/mtab see below :

/dev/root / ext4 rw,noatime,data=ordered 0 0
devtmpfs /dev devtmpfs rw,relatime,size=437228k,nr_inodes=109307,mode=755 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,relatime 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /run tmpfs rw,nosuid,nodev,mode=755 0 0
tmpfs /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0
tmpfs /sys/fs/cgroup tmpfs ro,nosuid,nodev,noexec,mode=755 0 0
cgroup /sys/fs/cgroup/systemd cgroup rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,nosuid,nodev,noexec,relatime,cpuset 0 0
cgroup /sys/fs/cgroup/cpu,cpuacct cgroup rw,nosuid,nodev,noexec,relatime,cpu,cpuacct 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,nosuid,nodev,noexec,relatime,devices 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,nosuid,nodev,noexec,relatime,freezer 0 0
cgroup /sys/fs/cgroup/net_cls cgroup rw,nosuid,nodev,noexec,relatime,net_cls 0 0
systemd-1 /proc/sys/fs/binfmt_misc autofs rw,relatime,fd=22,pgrp=1,timeout=300,minproto=5,maxproto=5,direct 0 0
debugfs /sys/kernel/debug debugfs rw,relatime 0 0
mqueue /dev/mqueue mqueue rw,relatime 0 0
configfs /sys/kernel/config configfs rw,relatime 0 0
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
/dev/mmcblk0p1 /boot vfat rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=ascii,shortname=mixed,errors=remount-ro 0 0
tmpfs /run/user/0 tmpfs rw,nosuid,nodev,relatime,size=88312k,mode=700 0 0

While my fstab is clean and neat with only what I want.

proc /proc proc defaults 0 0
/dev/mmcblk0p1 /boot vfat defaults 0 2
/dev/mmcblk0p2 / ext4 defaults,noatime 0 1
# a swapfile is not a swap partition, no line here
# use dphys-swapfile swap[on|off] for that

##USERMOUNT

Obviously, I am stuck at this point as trying to purge mtab (/proc/mounts) seems a daunting task to say the least.

I’ve tried twice to reinstall and do fs extension on very first access to the GUI but same result both times so I believe that the script has a serious problem.
So far I manually extend the second partiton on my main computer with gparted as a countermeasure.

Help would be appreciated to correct the file system extension script !