Firefox window size question

I have Tiger, and I use Firefox as my primary browser.
When I open FF, the window does not fill the entire screen. It does not extend all the way to the bottom or the right, leaving the dock and the HD icon uncovered. The Dock is always "on top" (so it does not matter if a window extends to the bottom) and I don't need constant access to the HD icon - I can just open it from the dock anyway.

Is there anyway to change this?

Just raise the window as high as you want and on the bottom right corner, you can drag it to expand and stretch. (height and width)

Yes, that is what I do. I want the window to open at that size. I guess there is no known way to do this

Once I resize a FF window, then close it, FF remembers the window size. When I open a new window, it is the size I resized it to, even extending all the way to the right side of the screen (obscuring HD icon). However, FF respects the Dock, and will only open to the top of the icons in the Dock (it does overlap just a bit). I resized my dock and no matter what size it was, FF opened a new window to overlap a certain percentage of the Dock (looks like about 20%?).