If you've downloaded Firefox 2.0 and like me you don't like the default tab behaviour don't despair there's a way to turn it off. To edit these 'hidden' preferences type about:config in the search bar and a list of preferences are displayed. Amend the preferences below by first searching for them in the filter text box then double clicking and amending.

browser.tabs.tabMinWidth = 0 to disable or reduce to < 100 to descrease size
browser.tabs.closeButtons = 3 to enable only a single close button on the right hand side.

Reference path:
Lifehacker disable tab scrolling -> QOT: Disable Tab Scrolling in Firefox 2 -> > Six tips for Firefox 2

Firefox Preferences Documentation

Part of Tip a day project