Workaround for OGG+AC3 in Oggmux with multiple streams

multiple, believe, English, produce, example

Well, I've spent a few hours digging these forums until I found out that OggMux and AC3 doesn't work very well.
(By the way this works quite nicely with OggMuxER, I'd just love to have the GUI of OggMux)

So, somewhere I read that if you mix the AVI and AC3 (with VirtualDubMod for example) then you can produce a valid OGM file. I believe that you can't still mux any others audio tracks...

But, my problem with that was that I was also muxing English and Portuguese subtitles.
So I was muxing:
stream1: AVI+AC3
stream2: PT subtitles
stream3: ENG subtitles

There is a problem here. I'm not sure what happens when I'm playing but it's something around this:
When I choose PT subtiles there's ENG showing.
When I choose ENG subtiles there's nothing showing.
So there is no way to show the PT subtitles.

My workaround in OggMux:
stream1: AVI+AC3
stream2: [not specified] Here I just pressed the Add button of the Subtitles group without specifing the file. What this is doing I believe is to create a stream holder for the AC3 stream. This could probably work instead of a null Subtitle, by adding a null Audio Stream.
stream3: PT subtitles
stream4: ENG subtitles

Works OK.