Ok, this is weird.
When viewing these forums in IE or FF, these forums show up normally.
However, in Chrome, the messages are limited to a quite narrow width. It looks like about 250 or 300 pixels wide for the message area, instead of taking up the full width of the screen.
It only happens in Chrome and it's only the PrimeGrid forums. When I go to the SETI forums, they look fine. It doesn't seem to be something inherent in the BOINC forum system, but rather something specific to the setup here.
My lucky number is 75898524288+1