Recent downtime (which is still ongoing for neolemmix.com but appears to be resolved for lemmingsforums.net) is due to a host issue. Downtime initially caused by urgent security upgrades, then extended by "a cabling/labeling/human error occurred during the followup, leading to similar issues which we are now working to correct".
Should be fixed soon.
Update: Neolemmix.com seems to be back up.