Transferring files froim Windows 7 to Windows server

We are trying to copy a file from Windows7 to a Windows server
The problem is that we always get an error.
We are trying to copy to a remote location called 'ROOT:/TEST'
But on the error it seems to add the directory name twice
ex: instead of 'ROOT:TEST/Test_sftp.txt.txt'.,
we see 'ROOT:/TEST/ROOT:/TEST/Test_sftp.txt.txt'.

This is the error we see in the log:
Cannot create remote file 'ROOT:/TEST/ROOT:/TEST/Test_sftp.txt.txt'.
. 2015-01-14 09:51:48.974 Error code: 3
. 2015-01-14 09:51:48.974 Error message from server: Permission denied

Would you know why the directory name is listed twice?
.
Thanks

I try another PC and it worked with the same release of WinSCP .. Same version and same URL and same accounts

I noticed that the SFTP-5 tab on the server side indicated
that the SSH Implementation was different:
One was OpenSSH_4.6 and the other was Vshell_3_5_4_630
Any ideas why ?

PC that does not work:
File transfer protocol: SFTP-5
Session Protocol: SSH-2
SSH Implementation: OpenSSH_4.6
Server host key: ssh-rsa

PC that worked:
File transfer protocol: SFTP-5
Session Protocol: SSH-2
SSH implementation: Vshell_3_5_4_630
Server host key: ssh-dss

Please attach a full log file showing the problem from both PCs (using the latest version of WinSCP).