From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.1) Gecko/20021003 Description of problem: I cannot resize a window using the top right corner of the window. How reproducible: Always Steps to Reproduce: Hover over top right corner of window. Note how pointer does not change to allow a resize of the window.
This is just how the Bluecurve theme is, it has the button all the way to the outer edge. If you change to a theme where the button does not cover the whole corner, then you will be able to resize. Even with Bluecurve, you can resize from the top right just below the button. i.e. position the mouse on the window border just below the close button.