AltGr leaks keypresses to VT on which X is running

Hi,

I recently observed this odd behavior:

I login as root on tty3 and run

loadkeys pl # like US QWERTY but AltGr changes a->=C4=85 c->=C4=87 etc.
echo        # only typed, not actually executed with ENTER

Now the last line shows the incomplete command:

$ echo=20

Then I login on tty1 and run

Xorg :0 vt3

which displays Xorg on vt3. Inside Xorg, while holding AltGr, I hit
every letter in order: qwerty...asdf...zxc..

Then I kill Xorg and switch to vt3. Now the last line shows:

$ echo =C4=99=C4=85=C5=9B=C5=82=C5=BC=C5=BA=C5=84

These are all AltGr-generated Polish letters _except_ =C3=B3 (AltGr+o).
No idea what's so special about =C3=B3. Pressing ENTER runs echo which
really prints this string.

Similar thing happens with German ('de') console layout. X layout seems
irrelevant.

It only happens if I first hold AltGr and then press a letter, not the
other way around.

Inside Xorg, all keys are processed correctly.

I'm not sure if it's a kernel bug, X bug or something "expected"?

Thanks,
Michal