Works awful on high traffic?

Does the data catch up later?

yes mostly, but the strange part is that it hasnt catches up yet, still 7 hours after it went down its still down.

Maybe the plugin is having concurrency issues. I also noticed that the plugin claims compatibility up 3.0.0. Are you using a higher WP version than that?

yeah im using 3.1. but the 7 days and 30 days stats works fine during high load, my site gets stumbled via stumbleupon 3-6 times / day and during that time tons of visitor visit the site and its only the “todays” stats that stops working.

My best guess is that it is a concurrency issue. I’d try to contact the developer though.

cannot find any contact info :/

That is unfortunate. You may end up having to fix it yourself, or pay someone to fix it, if you really want to use the plugin.