Am 07.04.2015 um 13:31 schrieb Alan BRASLAU <alan.braslau@cea.fr>:

On Tue, 7 Apr 2015 12:39:08 +0200
Wolfgang Schuster <schuster.wolfgang@gmail.com> wrote:

Am 07.04.2015 um 12:29 schrieb Alan BRASLAU <alan.braslau@cea.fr>:

On Tue, 7 Apr 2015 11:46:06 +0200
Wolfgang Schuster <schuster.wolfgang@gmail.com> wrote:

MWE:

\setupbodyfont [dejavu,10pt]
\starttext
\startitemize [n]
\dorecurse{10}{\startitem X\stopitem}
\stoptext

(switching to 100 items is even worse!)  

You missed the \stopitemize after the last item.

Just in the email (and so-called MWE)
but not in the test (and my applications).

Adding the missing \stopitemize in the MWE above
does not change the problem.

When I add \stopitemize to your example and use the fit option which
is missing in your example there are no problems in the output but
you have to use the distance key to put a space between the last item
number and the content.

\setupbodyfont [dejavu,10pt]
\starttext
\startitemize [n,fit]%[itemalign=flushright,distance=\spaceamount]
\dorecurse{100}{\startitem X\stopitem}
\stopitemize
\stoptext

"fit" is without effect,
so it is distance= that does not have a reasonable default.

Other fonts are not so bad, but dejavu (which is a bit larger)
looks really bad, by default.