Comment 39 for bug 985065

To me it looks like a bug in the server. Look at the file out_gnome.xkb provided by bryce:

...
xkb_symbols "pc+fr(oss)+us:2+inet(evdev)" {
...
    key <AD01> {
        type[group1]= "ALPHABETIC",
        type[group2]= "FOUR_LEVEL_ALPHABETIC",
        symbols[Group1]= [ q, Q ],
        symbols[Group2]= [ a, A, ae, AE ]
    };
...
So, symbols are screwed, fr is supposed to be in the 1st group, but in reality they are in the second group (American Qwerty vs French A)

At the same time, the xkm file attached by Sebastien, once converted to xkb ("xkbcomp in.xkm -xkb out.xkb") has:
...
xkb_symbols "pc+fr(oss)+gb:2+inet(evdev)+group(shift_caps_toggle)" {
...
    key <AD01> {
        type[group1]= "FOUR_LEVEL_ALPHABETIC",
        type[group2]= "FOUR_LEVEL_SEMIALPHABETIC",
        symbols[Group1]= [ a, A, ae, AE ],
        symbols[Group2]= [ q, Q, at, Greek_OMEGA ]
    };
...
Which is correct! So, once that xkm file is fed into X server, it swaps the groups. At least that's the only explanation I can give, for now. If everyone agrees with that, I would forward that bug to xorg server, Input/XKB component. If someone has better ideas - please let me hear them!