keyboard not working when using certain rdesktop options

[kläuser]

First of all, this problem *only* occurs on the login screen of the Windows client. If I succeed logging into the client, the keyboard works fine.

The scenario:

I just updated the host from Ubuntu 14.04 to 16.04. On 14.04 I never saw this problem. Maybe I should mention, that I upgraded Virtualbox also from 4.3.x to 5.1.4.

I have some headless Windows guests (Win 7, Win 10) - all of them have the same problem.

When I now try to connect from a Linux machine:

rdesktop -a 24 -g 1600x950 -z -N -xl -u klaus -d gbr 192.168.1.30

I see the welcome (login) screen and I'm able to use the mouse, but I cannot type in a password.

I can workaround this using the -p option:

rdesktop -a 24 -g 1600x950 -z -N -xl -u klaus -d gbr -p - 192.168.1.30

but thus is nasty, as you cannot put such stuff into a menu item (putting the password in plain text would help, but us at least as nasty).

Strange to say, that this phenomenon does *not* occur, when I omit all those user related options (-u, -d, -p). When using this commandline:

rdesktop -a 24 -g 1600x950 -z -N -xl 192.168.1.30

everything is fine. I see the login screen and can type in my credentials. Unfortunately I have to type in all the stuff now (user, domain, password) each time ... that's annoying, but it works .... as long as noone uses one of the -u, -d, -p options. If anyone tries to connect using one of these options, the keyboard is dead at the login screen for all subsequent connects. I need to poweroff/startup the guest machine to get this working again.

This is reproducable with rdesktop 1.7.1 (e.g. on LinuxMint 17.1) as well as with rdesktop 1.8.3 (e.g. on Ubuntu 16.04). Therefore I'd say this is no rdesktop problem but rather a problem of virtualbox. I unfortunately haven't found possibilities to debug/trace those connections - that would possibly give us some more informations...