I've built another example clearly showing the issue with character
alignment in natural tables.

Compare table 1 and table 4 in the attached PDF : the source code for
these tables is exactly the same, but they are not rendered
identically in the PDF (table 1 content is correctly aligned, contrary
to table 4). It's not normal the same table is not rendered the same
way.

When I remove tables 2 and 3, table 1 and 4 are rendered identically
(no more alignment problem).

Does someone know how to fix that?

Thanks a lot,

Nicolas Grilly