Divx plugin - local page + local divx file = file not found

Opera 9.1 - WinXP - npdivx32.dll - 1.3.0.0

Save this page and movie.divx to your desktop and load this page locally.
The markup specifies that movie.divx is in the same directory as this page, but it can't be found by the plugin.
Click on the video area to activate the object. Then, right-click and choose "Save video as".
In Opera, the filename will be localhost_movie.divx.
In Opera, file URIs start with file://localhost/. In other browsers they start with file:///.
To find movie.divx, the plugin determines the current directory from the location of this page. It appears the plugin is choking on the "localhost" part of the page address. However, the file can still be found in Firefox when using a file://localhost/ URI to this page, so it may be something else causing the problem in Opera.