[XeTeX] Problem with font features in tables

[Will Robertson]

On 2009-02-04 05:04:12 +1030, "Michael Lynch" 
<michael.s.lynch at googlemail.com> said:

> \newcommand{\fullcaps}[ 1
> ]{{\addfontfeatures{Letters=Uppercase,Numbers=Uppercase}\MakeTextUppercase{#
> 1}}}
> 
> These both seem to work fine, particularly when used in body text.

By the way, in this case, you don't need the "Letters=Uppercase" 
feature; few fonts support it and \MakeTextUppercase does the same 
thing for you anyway.

> However, for my document, they are both used for the first time in a table.
> The problem occurs when my "fullcaps" command has not been used in the body
> text first. If I run it on my sample document (Test.tex), it does not
> produce "full caps" numerals as I'd expect. If however, I include a
> \phantom{\fullcaps{}} command prior to the first table, it works as I'd
> like! This isn't a problem to do, and seems to have no effect on the final
> layout, but I wondered if anyone could explain why it does this?

Hmmm. This is REALLY REALLY weird.
The problem only happens with tabularx, not tabular.

I'm going to have to look into it...and it might be a while until I get to it.

Thanks for letting me know,
Will