The corners look to be using background attributes in the TD tags. PhotoPlog doesn't support that attribute as it's depreciated, so you can either replace things like:
Code:
Content visible to registered users only.
With things like:
Code:
Content visible to registered users only.
Or you can find the following in the settings.php file:
Code:
Content visible to registered users only.
And replace with:
Code:
Content visible to registered users only.
For the /forum/forum thing, try using /forum in the PhotoPlog Duplicate Directory setting.