Collapsed borders disappearing in Opera 7

When using rowspan

[grahamstewart]

I'm creating a table (yes... for tabular data.. its for a list of jobs). Anyway when I was styling it I came across what I think is an odd bug in Opera 7.

HTML (4.01 Strict):

[pre]
<table>
<tr>
 <td class="title">one</td>
 <td rowspan="2" class="date">three</td>
</tr>
<tr>
 <td class="subtitle">two</td>
</tr>
 
<tr>
 <td class="title">one</td>
 <td rowspan="2" class="date">three</td>
</tr>
<tr>
 <td class="subtitle">two</td>
</tr>
</table>
[/pre]

CSS:

[pre]
table {
border-collapse: collapse;
}
td.title, td.date {
border-top: 1px solid black;
}
td.subtitle, td.date {
border-bottom: 1px solid black;
}
[/pre]

The problem is that the border disappears between the 'subtitle' of the first entry and the 'title' of second.

It re-appears if I use the the border-collapse:separate model and it is fine in IE6 and NN7.

All html and css is validated and is correct.

Any suggestions?

[grahamstewart]

To further explain, the table should look like

----------- 
one 
   three 
two 
----------- 
one 
   three 
two 
----------- 

But in Opera it looks like..

----------- 
one 
   three 
two 
       ----- 
one 
   three 
two 
-----------