ssh crashes connecting using host names on windows

On a new install of Windows Server 2008, I attempting to use ssh to connect to another host. I have installed putty/openssh. This works without a problem when trying a command such as:

ssh 192.168.0.2

However, this will crash when trying something like:

ssh testserver

with the error as follows in the windows event viewer:

Faulting application ssh.exe, version 0.0.0.0, time stamp 0x40843497, faulting module kernel32.dll, version 6.0.6001.18000, time stamp 0x4791a76d, exception code 0xc0000005, fault offset 0x0004bbb8, process id 0xe94, application start time 0x01cb873195e795d5.

Any suggestions? thanks in advance

I have now resolved this myself- I had been using the openssh package from http://sshwindows.sourceforge.net/

I uninstalled this, installed cygwin and the ssh package within this. Updated my system env path, to use this, and just like that- its working :)