It's a little early for Pesach, but anyway

Dov Bear links to a dispute on Kashrut.org over whether men and women ate the Korban Pessach seperately, or not.
How this rather bizarre question came up I have no idea, but it does remind me of a very interesting Dvar Torah I once read. I'm not sure if I remember it all, but this was the gist:
The original fourth question on Seder night ('Bein yoshvin uvein mesubin') was nothing to do with reclining, but rather, "On all other nights we eat meat which has been roasted, stewed, or boiled, but on this night we eat only roasted meat" -- ie. the Korban Pesach. Clearly, it was dropped once we no longer really ate the Pascal lamb, but the question about reclining only came later -- at a time when reclining while eating was no longer the practice.
If 'Kulanu Mesubin' probably does not mean, 'we are all reclining,' then, what does it mean?
The answer I read claims the words 'Kulanu Mesubin' mean, 'we are all gathered together,' from the same root as 'mesibah' (party). The clincher, of course, is that the word is used in that sense (according to many translations) just a little bit further on in the Haggadah -- 'Ma'aseh beRabbi Eliezer VeRabbi Yehoshua.... shehayu mesubin BiBnei Brak' -- 'It is told of Rabbi Eliezer and Rabbi Yehoshua... who were gathered in Bnei Brak.' Interestingly, I see also that my Hebrew-English dictionary (which I don't think I've ever used before...) translates 'Mesubin' as 'Diners at a table.'
One thing that's always bothered me about this idea is that it depends on translating the word 'yoshvin' as 'sitting alone' -- which I'm not quite sure how you can. Nevertheless, I'd rather not let the facts get in the way of a really neat theory. Can anyone make it work????