On Mon, May 5, 2014 at 2:25 PM, Stefan Monnier <monnier@iro.umontreal.ca> wrote:

It still seems to point to an underlying bug in timer.el, even if it is
only triggered by "not kosher" code.
Would it be possible for you to try and extract a reproducible recipe from
your (old) code?

Yes, probably. I think I reported such a bug long ago. (But I was never able to understand how it worked.)