Control_L and Control_R release same?

["Kelvin Lao" <kelvinlao at hotmail dot com>]

Hello.  I recently noticed that if I ssh to my linux box and do this:
Hold down left control key and press and release x
While still holding down the left control key, press and hold down the right 
control key
While still holding down the right control key, release the left control key
Press and release c

That works as expected.  I get a ^X^C.  But, if I start up an xterm and 
repeat the same steps, I get: ^Xc

It seems that when going through the X client that the release of either 
control key generates the same key release signal.

Why does this matter?  I am a little fast and sloppy while using emacs.  
When my fingers happen to land on both control keys at some instant, the 
next control character I think I am typing comes out as the unmodified 
character.  Very annoying.

This same behavior does not happen if I run an X client from a linux box, 
only when running from Windows and attaching to the linux box.

Any suggestions?
Thank you for your help.
-k