I have been searching the net about border-collapse. And it seems it does not really collapse the border on nested table. I wrote a sample HTML and it seems to be ignoring border collapse.
I found a related question here but it seems it is not solved. link text
<html>
<head>
</head>
<body>
<p>dsafhidsljfalkdsjfklsdajfkjsdakl jdsfjasdklfasdkljfkl</p>
<table style="border: solid 1px #000000; border-collapse: collapse;" cellpadding="0" cellspacing="0">
<tr>
<td>
<table style="border: solid 1px #000000; border-collapse: collapse;" cellpadding="0" cellspacing="0">
<tr>
<td>
A
</td>
<td>
<input type="text" />
</td>
</tr>
<tr>
<td>
B
</td>
<td>
<input type="text" />
</td>
</tr>
</table>
</td>
</tr>
</table>
</body>
</html>
Supplementary Info (based on somacore and moo's comment): I already used the "border: none" in the internal table to solve this problem. But on some designs, it is not just one nested table. For complex web pages, it needs upto 3 to 4 nested table levels to design the GUI. And inside those nested tables, not all cells uses border. I had just used a simple example for the problem.
Is there any other solution that hand picking merging adjacent borders to one?