Sftp error

[r600]

Hi All

Currently using a fedora linux core 3.

I have set up a ftp/sftp server on this box

We have 3 sftp customer currently connecting to this box using Cuteftp with no problems.

A four is trying to connect using sftp and gets the following error.

debug: Remote version: SSH-1.99-OpenSSH_4.2-chrootssh
debug: OpenSSH: Major: 4 Minor: 2 Revision: 0
debug: Ssh2Transport/trcommon.c:1518: All versions of OpenSSH handle kex guesses incorrectly.
debug: Ssh2Transport/trcommon.c:1661: Algorithm negotiation failed for c_to_s_compr: client list: zlib vs. server list : none,zlib@openssh.com
debug: Ssh2Transport/trcommon.c:1661: Algorithm negotiation failed for s_to_c_compr: client list: zlib vs. server list : none,zlib@openssh.com
debug: Ssh2Transport/trcommon.c:1901: lang s to c: `', lang c to s: `'
debug: Ssh2Common/sshcommon.c:168: DISCONNECT received: Algorithm negotiation failed.

I have been told this customer can only connect using SSH2.

Is the error because I need to upgrade the SSH-1.99 version .

I have put the lastest version of openssh (openssh-4.2p1)on but this does not change the version 1.99.

Can any help ?

Also can any recommend any good books on linux ?

Many Thanks