columns collapsed in Firefox 1.0

Rather than seeing contiguous vertical lines separating each column, what I'm seeing is each cell in each row collapsing to the left, with all white space eliminated in each row, such that the column vertical lines stagger from row to row. Any idea what might be causing this?
Thanks,
Rich

In addition, I'm experiencing the exact same thing with my website when using Netscape 8.0.2.
The only thing I've really done to change the grid layout was to change settings to hide the header row (as explained from your documentation).

IN addition, when using Netscape 7.1, the table does not appear at all... Yikes!

Hope you can help,