is there a reason you are using netscape over firefox
? firefox is the better option. or if you need/want email and the other programs integrated, get the current version of mozilla
second, if you are opening multiple windows, you are defeating the purpose of tabbed browsing. in tabbed browsing you open one window, and then open multiple tabs in that one window. much easier to organize things in tabs than with a cluttered taskbar.
it sounds like your issue is coming from the fact that you are closing the entire tab bar, rather than closing the individual tab you no longer need. try closing the individual tab instead. normally, you can do this by simply double clicking the tab.
however, if you still want to use multiple windows, there is an extension for mozilla and firefox that will give you more control over your tab bar. you can get that here:
see the extensions link on the left.