After upgrading to lucid, I see:
$ xmodmap -pm
xmodmap: up to 4 keys per modifier, (keycodes in parentheses):
shift Shift_L (0x32), Shift_R (0x3e)
lock Caps_Lock (0x42)
control Control_L (0x25), Control_R (0x69)
mod1 Alt_L (0x40), Alt_R (0x6c), Meta_L (0xcd)
mod2 Num_Lock (0x4d)
mod3
mod4 Super_L (0x85), Super_R (0x86), Super_L (0xce), Hyper_L (0xcf)
mod5 ISO_Level3_Shift (0x5c), Mode_switch (0xcb)
But it makes no sense for Super and Hyper keys to both be associated with mod4. I see mod3 is free. Why not have the Hyper_L key on mod3?
It also looks odd to have two Super_L keys in the map, and to have Meta and Alt on mod1.
XEmacs gives these warnings:
(2) (key-mapping/warning)
Two distinct modifier keys (such as Meta and Hyper) cannot generate
the same modifier bit, because Emacs won't be able to tell which
modifier was actually held down when some other key is pressed. It
won't be able to tell Meta-x and Hyper-x apart, for example. Change
one of these keys to use some other modifier bit. If you intend for
these keys to have the same behavior, then change them to have the
same keysym as well as the same modifier bit.
(3) (key-mapping/warning) XEmacs: Super_R (0x86) generates Mod4, which is generated by Hyper.
(4) (key-mapping/warning) XEmacs: Super_R (0x86) generates both Mod3 and Mod4, which is nonsensical.
Status changed to 'Confirmed' because the bug affects multiple users.