Brimosoft

Some users are reporting 404-not found 403-forbidden errors when they activate ‘fancy’ permalinks.
If your gallery page has the same name as the gallery folder, your server will attempt to show the content of the folder instead of your wordpress page. Please make sure the names are different.
Another trick, that works most times, is to put index.php in the gallery URI in the Lazyest Gallery settings.
Like this: http://myblogsite.com/gallery to http://myblogsite.com/index.php/gallery