Re stats: For those two plugins, there aren't enough active users of either one to produce meaningful statistics.
What you're seeing is basically the "null" result. To be specific, there's only two recorded users of myposeo-dashboard (one of which is active) and eight recorded users of yd-wpmu-bloglist-widget (again, one of which is active).
The stats are accurate, to a point. When there's nobody using the plugin, or nobody that has reported back recently, then stats won't be meaningful.
That said, the data gathering system is not perfect, and some data may be lost. We only retain the data for a week, tops. So if nobody reports in in that week, then we think nobody's using it.
The Last Updated date is supposed to be updated from the SVN, but it's possible that there's a bug there preventing it from updating sometimes. I'll try to figure it out. Regardless, that date has no actual effect on anything meaningful like upgrades and such. It's basically for display purposes only.