My question comes from a problem:
I Use Xming on Windows 7 to connect to a Linux host (through PuTTY) in order to start and display a gnome-terminal. I have some troubles using the Windows clipboard:

• Copy from Windows to Xming works well. (Ctrl-C then middle-click on Xming)
• Copy from Xming to another Xming cession works with delay. (Selection on Xming then middle-click on the other Xming)
• Copy from Xming to Windows works most of the time with delay. (Selection on Xming then Ctrl-V on Windows)

On Windows: I have to repeat the Ctrl+V many times before it passed my text. (<10 kBytes)
Note that firsts failing attempts don't past the previous clipboard content.
Note 2: If I use a VB script to paste the clipboard content I have no delay.

Set objHTML = CreateObject("htmlfile")
ClipboardText = objHTML.ParentWindow.ClipboardData.GetData("text")
path = "D:\Users\blanchj1\AppData\Local\Temp\clipboard"
Set objFSO = CreateObject("Scripting.FileSystemObject")
Set objFile = objFSO.OpenTextFile(path, 2, true)
objFile.WriteLine ClipboardText
objFile.Close

Note 3: If I paste through an application menu ex notepad++ -> edit -> paste, I still have this delay.
Note 4: If I paste the content with Ctrl+V a second time, I still have this delay.
Note 5: The delay seems proportional to the number of charters to paste.
So I suppose this delay comes from a windows issue. Is that a problem of characters-encoding conversion?
Who can explain to me how it works?