It was solved. I just report it here in case it is useful to others.
It turned out to be a problem with the language environment.

Previously, the language environment was detected to be Chinese although my system-default language is English. The preferred charset for Greek letters was then set to a Chinese charset, which leads to wrong widths I guess. After I set the language environment to utf8 in the init file, everything works fine.

PS: sorry for duplicated emails, forgot to "reply all" in the first reply.

Jiang


On Sep 5 2016, at 11:06 pm, Nicolas Goaziou <mail@nicolasgoaziou.fr> wrote:

Hello,

jsj <jsj.register@gmail.com> writes:

> To make it clear, the behavior I reported can be reproduced with a clean init file with just org loaded.
>
> I put the table
>
> | a | b | c |
> |--------+---+---|
> | \alpha | | |
>
> in an org file, toggle pretty entities by C-c C-x \, then C-c C-c to realign the table. The result I get is
>
> | a | b | c |
> |----+---+---|
> | α | | |
>
>
> If I try the same thing for
>
> | a | b | c |
> |--------------+---+---|
> | \alpha \beta | | |
>
> I get
>
> | a | b | c |
> |-------+---+---|
> | α β | | |
>
> Is it just me or you can reproduce the same behavior?

I cannot reproduce it.

However, I fixed an alignment bug in tables recently. Does updating Org
solve your issue?

Regards,

--
Nicolas Goaziou