not great but something like this might be better.
http://www.radioshack.com/product/index.jsp?productId=2062217

design not size or material.

or this is not too bad, but I would seal the sides.
http://electronicsusa.com/miniboxes4.html

if the insides of your first one look like this
http://www.okwenclosures.com/products/okw/robust/RB_G.jpg
then it isn't a big deal since the screws are outside the box area.

if not something like that or this
http://www.okwenclosures.com/products/okw/smart-box.htm