Looking at your page in both Firefox 1.5.0.10 and IE6, they both show a red and a blue block with a thin white line between them in the first two cases, and butted up against each other in the third case. Is that what you're seeing?
I don't think you're seeing a "border". I think you're seeing either cell padding or cell spacing. To review terms, from the inside (cell content) to the outside (neighboring cells) you have:
- cell padding
- cell border
- cell spacing
If any of those are nonzero width, you'll see something. Only in the third case did you set all three to zero. Can you set the
border color (through CSS, probably) to black so we can confirm there's no border there? Now, the question is, "why is there a pixel or two of padding and/or spacing?" Is there any CSS I'm not seeing anywhere?
padding: n controls cellpadding, and
border-spacing: n controls cellspacing. Just for giggles, try taking out the "style1" CSS setting and see if it makes any difference (I would not expect it to).
Cell padding and spacing are supposed to default to 0, as is the border width. Why you're getting something puzzles me. I would
expect flakiness from IE, but Firefox behaves the same way.
GOT IT. My HTML book says the cellpadding is supposed to default to 1 and cellspacing is supposed to default to 2. You must explicitly give 0 values to have everything close up.