Yes strange indeed you say that you have not altered anything but your site shows you have in the body properties your background is dark the header etc so I assume you changed a color to white to have it show on that dark background and hense that is the issue.
The default vb
color scheme with that light style with blues and whites is a light grey background and black text. Hense the popup menu is black text on white background
Yours is now with your alterations white with white text which is why you can not see anything. I hope that makes sense.
With a default style install from vb
it will look as it displays on my site Main Index - PhotoPost Classifieds