Menu items always >= 20px high?

[Sue D. Nymme]

I'm new to coolTree, so maybe I'm doing something wrong. Using the standard (non-professional) version.

I have a two-level text-only tree. I am having difficulty when I change the size of the text font in the sub-items. If I use a 20px font, the <td> cell for each sub-item is 23 px high, and the <a> for each menu item is 22 px high. This is reasonable. If I use an 18px font, the <td>s are 21px high and the <a>s are 20px high. If I use a 16px font, the <td>s are 20 px high, and the <a>s are 19px high. If I use a 12px font, the <td>s are 20 px high, and the <a>s are 15px high, and things start to look pretty crappy (mouseover highlighting looks and feels awful).

If I use an 8px font, the <td>s are 20px high, and the <a>s are 10px high. This makes a huuuuge gap between each item. It looks awful.

What'm I doing wrong?
Below is the format structure I'm using:

var NAV_FORMAT =
[
//0. left position
10,
//1. top position
40,
//2. show +/- buttons
false,
//3. couple of button images (collapsed/expanded/blank)
["/img/b.gif", "/img/b.gif", "/img/b.gif"],
//4. size of images (width, height,ident for nodes w/o children)
[1,1,0],
//5. show folder image
false,
//6. folder images (closed/opened/document)
["/img/b.gif", "/img/b.gif", "/img/b.gif"],
//7. size of images (width, height)
[1,1],
//8. identation for each level [0/*first level*/, 16/*second*/, 32/*third*/,...]
[0,0],
//9. tree background color ("" - transparent)
"rgb(105,150,109)",
//10. default style for all nodes
"nav-top-node",
//11. styles for each level of menu (default style will be used for undefined levels)
["nav-top-node", "nav-sub-node"],
//12. true if only one branch can be opened at same time
false,
//13. cellpadding, cellspacing
[0,0],
];