I can not reproduce resizing the window and having the export name and options all disappear.
Try putting the focus in the export window and typing shift + O (hotkey combination for the options dropdown).
ALso, the lower right corner with the triangle of dots does nothing?
Other options:
1) spend some time with tech support
2) get into the registry and try to reset that specific window settings (always a dangerous thing)
3) rename or delete the Normal.mxt - This will reset all windows, toolbars, and customizations to original install settings.
Regards, and good luck!
Jim