I have almost the same Problem. Habe a Linux Server wit 3.6.1p1 Openssh installed and openssl 0.9 installed. I can connect with SSH1 but not with SSH2 . Tried another program SSH2Pro as a client, and this worked. But I prefer your SW as it is great (FTP like and Freeware)
Below is my log file for Winscp2.20 ..(by the way I am using the Winscp with my Linux and SSH1. Working Perfect. Thanks for your great Freeware .)
. Reading private key file "C:\WINDOWS\Profiles\music\Desktop\t\privatejob.PPK"
. Offered public key
! Server refused our key
. Server refused public key
. Keyboard-interactive authentication refused
! No supported authentication methods left to try!
. No supported authentications offered. Disconnecting
* (ESshFatal) Not connected!
Are you sure that privatejob.PPK key is registered as authorized SSH2 key on your server?