Hi,

run the included test file using

emacs -Q -l timer-test.el

and then open the generated dribble file /tmp/mydrib.  On my computer,
it looks something like

0000000000000000001111111111111111111222222222222222222223333333333333333444444444444444444555555555555555556666666666666666667777777777777777778888888888888888899999999999999999

which means that of 4000 events having an effect in the scratch buffer,
about 5% (a non-deterministic amount) are actually recorded in the
dribble file.  In particular, it looks like only the first of several
events placed into unread-command-events at one point of time will ever
see the dribble file.  While I am only moderately interested in actually
generating a useful dribble file, the same holds for macro recording.
And I have an actual application which is severely impacted here.

Note that _all_ of the events (usually) are actually processed as input
in the *scratch* buffer.  It is only the recording of them which falls
really, really flat on its face.