Warning: The BORDER Attribute in Netscape
There is a bug in the Netscape implementation of tables that goes all the way back to the first version of Netscape that supported tables (Navigator version 1.1). According to the specification, a table that has CELLSPACING set to zero should have no space between the cells. In the Netscape browser, there is still space if you have not explicitly set BORDER=0.
The default value of the BORDER attribute should be zero, but it's not in Netscape Navigator. Even if the border is not rendered, it still takes up space unless you set it to zero. Other browsers may emulate this behavior.