Storage [Q] Optimus L5 II (E460: impossible to enter the passwords for backup with Holobackup

Hello all. I have unrooted LG Optimus L5 II E460
Android 4.1.2
Kernel 3.4.0
E 46010m-EUR-XX

and I have been trying to backup with Holo backup

The OS of my PC is Mageia release 3 (Official) for i586 Kernel 3.10.24-desktop586-2.mga3 on a 4-processor i686 if it matters.

After I click on one of the buttons in Holo Backup window and I get the message "Now unlock your device and confirm the backup operation." on the console of my PC, on my LG I get messages asking for passwords (one for unlocking the device, and another for restoring later). This is slightly different from what I saw on a tutorial but probably this is not a problem. The problem is that when I try to enter the password, and hit enter/return key, LG seems to consider that it is a part of the password Thus the zone to hit to confirm the backup remains grey, and I can't proceed any further.

I thought using TAB key instead of ENTER might help, so I installed Hacker's keyboard, but the TAB key make the cursor go between the two zones for passwords, and I am still unable to proceed any further.

Would anyone know any way to get around this problem? Thank you very much in advance.