See message on project's main board. They've been having sporadic crashes. The suspension is ostensibly to fix that problem. More seriously, the project managers believe that there may be computational errors as well. They won't let it run again until it's all ironed out.

I personally have respect for PM's that will take this step, rather than letting it slide along, creating questionable science, which would eventually ALL have to be thrown in the bin. There's plenty of useful, deserving projects out there. Just pick one until they're back up.