pagelayout.tpl seems to have no effect

Hi,

Using 3.4.1, adding pagelayout.tpl to the design/mysite/templates doesn't appear to have any effect. I also tried adding it in design/mysite/override/templates with no success.

I noticed that in settings/siteaccess/mysite/site.ini.append.php there is the following:

[DesignSettings]
SiteDesign=mysite
AdditionalSiteDesignList[]=base

"base" is definitely being used. How do we override this and why is it even there?

Help!