I don't know as (as a Pro-user) I usually don't download Free version so I don't have them on my HD.
However, if you're using VMR (or EVR?) video rendering mode, you could try setting
Alpha blending value to zero.
This is under (rightclick >) Options > Preferences > Video > [OSD].
Or alternatively
this old post of August 2003 may perhaps help you a wee bit.