Core FTP

Hi all,
we got the following message after conecting via ssh with public key
the complete command are:
pscp -v -r -i \\pfadto\ssh_keys\username@id_rsa.ppk username@serverip:/outgoing/* \\pfadto\importexport\IMPORT
-----------------------------------
Looking up host "serverip"
Connecting to serverip port 22
Server version: SSH-2.0-CoreFTP-0.1.2
We claim version: SSH-2.0-PuTTY_Release_0.59
Using SSH protocol version 2
Using Diffie-Hellman with standard group "group14"
Doing Diffie-Hellman key exchange with hash SHA-1
Server"s host key did not match the signature supplied
Fatal: Server"s host key did not match the signature supplied
----------------------------------

The CoreFTP Server Build 279 running on Windows Server 2003

I hope to post all informations to solve this problem

Thank for your anwser.
I forgot to say, normaly it works, the server key is ok.
This problem comes from time to time , often daily. After restart the CoreFTP service it works. But it is not so conftible to get a message from our customer: the server doesnt work...
have anybody a idea to solve this problem?

Thanks a lot
Uwe

The installed build is 279.
Maximal Conections are 255
Max Connections per IP is 5

Thanks a lot for the Build 282, it works
Best regard
Uwe