Again, I have no expertise on this. Just saying, via a sort of reasoning-by-metaphor, that it seems possible to me that rather than missing matter it could be a misapprehension about the nature of the "rules" that govern the behaviour of the universe. In that respect, this seems interesting and relevant.
Exclusive: Paper by UCL professor says ‘wobbly’ space-time could instead explain expansion of universe and galactic rotation
www.theguardian.com
[EDIT] heh, had to use the search function to find where this issue came up - didn't realise it was deep in the Michigan/Gaza thread. Fair to say this is going a _trifle_ off-topic.