Missing Page Check not working.

[Ch4iS]

My site which was upgraded from V1.3.9 to V1.5 and also now a fresh V1.5 install both have a problem of the missing page check not working. (just get a blank page)

Setting the options to either of these below does not change anything for a missing page.

On = Send missing pages to 'index'
Off = Don't check for missing pages
Page Not Found = display the Page-Not-Found page


At first I thought maybe something didn't copy over correctly when I upgraded so having some free time I did a fresh install of V1.5 on a separate database and I still have the problem of it not working.

Is there something extra I should be doing? adding a .htaccess file to the main directory? or could this be an issue with the server I am on? (Host is AusWeb with the Starter package)