Forum: IronRuby Why some mailing list items aren't showing up in forum?

I usually use the IronRuby forum interface (I find it easier to browse
through):

http://www.ruby-forum.com/forum/34

But I just noticed today that there are a number of items that are ONLY
showing up in the normal mailing list/archive:

http://rubyforge.org/pipermail/ironruby-core/2009-...

Any ideas on why this is occurring/if it was already a known issue?
I just thought the mailing list traffic was slow lately.
For now, I'll check the mailing list archive only, thanks.