Hi wvmikep!
>>The IE Problem: There's a gap between
>>the right edge of the table and the scrollbar
>>of the browser. (works in Netscape)
I have IE5.0 and don't see any gap.
>>The Netscape (4.7) Problem: The black
>>vertical lines (left and right side of menu)
>>are displaying as too wide. (works in IE)
Sometimes weird things happens...
I also seldom encounter such problems, and think that there's no any stardart way to solve it - you have to play with it in every particular case.
For this one I can suggest this: change your code for that table colomn with blank.gif image:
<td valign="top" bgcolor="Black" width="1"><img src="images/blank.gif" width="1" height="1" alt="" border="0"></td>
1. Create a new image with width of 10-15px (in this particular case you have enough space for it). It should be white (or any transparent color) with black vertical line at it's right corner. This line will be your right side navigation border.
2. Put it to the background of this table cell:
<td background="newbackgr.gif">& nbsp;</td>
Sometimes it's good to create a CSS class for this cell:
.thiscell { font-size: 1pt }
it's because the default size of text (as well as & nbsp

is larger than you may expect and it cause extra gaps or width. Here you may not need it because of wide background image, but note this trick - it may help you in future.
You may also use transparent .gif (as you did) instead of nonbreaking space.
I think that this will help you to solve a problem.
In addition I have to add that the page looks not bad at all. And there are no differences in IE5, Netscape6 (it has no problems mentioned) and Opera5.
The code looks good too, and I agree with you in use of transparent gifs where it make sence and % in width values.
Good luck!
Andrew | starway@mail.com