Comment 39 for bug 393012

I have the same problem, but with perhaps a bit more information.

I am able to copy files using nautilus to a samba share hosted on XPsp3 or earlier. The bug is only present (for me) when copying to a share hosted on Windows 7 or Server 2008r2. Something to do with the new authentication requirements?
I am able to copy files to the share using smbclient, or even the cp command to ~/.gvfs/sharename.
The bug only exists when using the Nautilus interface. The mount point created by Nautilus/gvfs also works fine.

* When copying to a Win7/Server2008r2 share via Nautilus:
  -files <48KB transfer correctly.
  -files >48KB transfer only the first 48KB.
* Copying via 'cp' to ~/.gvfs/sharename completes successfully.
* Copying via 'smbclient' completes successfully. ie: smbclient \\\\server\\share > cp foo.txt foo.txt
* Copying via 'mc' completes successfully.

Steps to reproduce:
1. Create a share on a Win7 or Server 2008r2 server.
2. Use Nautilus to browse to the share.
3. Copy file >48KB.
Result "Invalid Argument"

OR:
1. Create a share on a Win7 or Server 2008r2 server.
2. gvfs-copy foo.txt smb://server/share/
Result "Invalid Argument"

In my case, I can not reproduce against WinXP or earlier.
This is clearly a problem with gvfs-copy.