Description of Problem:
I have a keyboard map that allows me to use Shift-Shift combination to
switch between English and Cyrillic keyboard maps:
% xmodmap -pk -pm | grep Shift
shift       Shift_L (0x32),  Shift_R (0x3e)
     50         0xffe1 (Shift_L)        0xfe0a (ISO_Prev_Group)
     62         0xffe2 (Shift_R)        0xfe08 (ISO_Next_Group)
Now if I start vncviewer, after the first time I use Shift (the single one,
not the Shift-Shift), vncviwer will start sending Shift-xxx events instead
of xxx events (for xxx in mouse click, Enter key press, etc).

How Reproducible:
Always

Steps to Reproduce:
1. Run 
xmodmap -e "keysym Shift_L = Shift_L ISO_Prev_Group" -e "keysym Shift_R =
Shift_R ISO_Next_Group" 
2. Start vncviewer
3. Press Shift-A, then (after Shift is released) press Enter (or click mouse)

Actual Results:
You get Shift-Enter (or Shift-mouseclick) event in the remote VNC session.

Expected Results:
You get Enter (or mouseclick) event in the remote VNC session.

Additional Information:
- I am using XFree86 v4 and KDE desktop. I do not have any problems like
that with any applications except for vncviewer.
- If I press F8 or leave vncviewer window and come back, the vncviwer
temporarily reverts to normal state (until I press Shift again).
- If I chose to use Shift-CapsLock combination for switching groups instead
of Shift-Shift:  
lock        Caps_Lock (0x42)
     66         0xffe5 (Caps_Lock)      0xfe08 (ISO_Next_Group)
that everything works (but I have to get used to using a new key combination).