Styling <tr> elements?

[august]

I've got a style sheet (won't include a reference here but it's simple) in which I'm trying to style every <tr> element within a table with the class attribute set to "general". What I'm doing is similar to this:

table.general tr{font-weight: bold; padding: 0.5em 0; border-bottom: 1px solid;}

And guess what? the font turns bold, but neither the padding nor the border shows up.

I'm using Firefox 1.X for Mac OS (Normally understands almost every style sheet). Is there something in the documentation that sais anything about borders and paddings not being applicable to <tr> elements specifically? If not, who's doing this to me, and why?

[NogDog]

Depending on the exact effect you're trying to achieve, perhaps what you need is:

table.general td {
  font-weight: bold;
  padding: 0.5em 0;
  border-bottom: 1px solid;
}

[august]

So borders and padding cannot be set on <tr> elements? If not, do you know why not?