ConnectBot 1.7.1 (installed from Google Play) on Nexus 7 with Android 4.1.2 Server with Gentoo 64 bits openssh v5.9_p1-r4

I try to import public key: id_rsa.pub (generated in my Ubuntu PC) and ConnectBot gives an error: it can't parse it. However I can import the private key.

But it can't connect with private key.

echo $TERM

xterm

uname -a

Linux ks212190.kimsufi.com 3.5.4-hardened-r1 #1 SMP Sat Oct 6 16:43:20 CEST 2012 x86_64 Intel(R) Core(TM) i5-2300 CPU @ 2.80GHz GenuineIntel GNU/Linux