This is a bug in XFree86 3.3.6.  The following code shows that
XtTranslateKeycode is not taking account of the CapsLock key.
   
main(int argc, char *argv[])
{  
    char *fallback[] = { (char *)NULL };
    Widget toplevel;
    Display *Display;
    XtAppContext app_con;
    XrmOptionDescRec Options[] = {};
    KeySym sym0, sym1, sym2, sym3;
    Modifiers mod0, mod1, mod2, mod3;
    KeyCode KeyA;
    int i, NumCodes;
    KeyCode *KeyCode;

    toplevel = XtAppInitialize(&app_con, "Test", Options,
XtNumber(Options),
       &argc, argv, fallback, NULL, 0);

    if(toplevel == NULL)
    {
       fprintf(stderr, "Failed to initialize\n");
   
}                                                                           
    Display = XtDisplay(toplevel);
    if(Display == NULL)
    {
       fprintf(stderr, "Failed to set display\n");
   
}                                                                           
    XtKeysymToKeycodeList(Display, (KeySym)0x41, &KeyCode, &NumCodes);
    for(i=0; i<NumCodes; i++)
    {
       printf("Keycode for 'A' is 0x%x\n", KeyCode[i]);
   
}                                                                           
    KeyA = KeyCode[0];
    XtTranslateKeycode(Display, KeyA, (Modifiers)0, &mod0, &sym0);
    XtTranslateKeycode(Display, KeyA, ShiftMask, &mod1, &sym1);
    XtTranslateKeycode(Display, KeyA, LockMask, &mod2, &sym2);
    XtTranslateKeycode(Display, KeyA, ShiftMask | LockMask, &mod3, &sym3);

    printf("Keysyms for 'A' are:\n"          "\tShift:\t\t%x  modifiers
returned=%d\n"
          "\tLock:\t\t%x  modifiers returned=%d\n"
          "\tShift+Lock:\t%x  modifiers returned=%d\n",
          sym0, mod0, sym1, mod1, sym2, mod2, sym3, mod3);
}                                                                               

----------------------------------------------------------
Output is:

Keycode for 'A' is 0x26
Keysyms for 'A' are:
       Unmodified:       61  modifiers returned=1
       Shift:              41  modifiers returned=1
       Lock:              61  modifiers returned=1
       Shift+Lock:       41  modifiers returned=1

---
Note that the Lock key has no effect on the KeySym.

          "\tUnmodified:\t%x  modifiers returned=%d\n"