If wikilinks are put in an external table file, those links are not seen at
scan time, and so ikiwiki does not know to update the page containing the
table when the pages the links point to change (are added, removed, etc).

There seem only two solutions to that bug -- either really make wikilinks
in an external table file not work (probably by escaping them), 
or run the preprocess code also in scan (expensive!). --[[Joey]]

[[done]]
