Database error with Prosites

My multisite went through a few minutes of 500 server erroring today.

When the host and I checked the error logs, the last error we were seeing was this

[21-May-2012 16:28:05] WordPress database error Multiple primary key defined for query ALTER TABLE wp_pro_sites_daily_stats ADD PRIMARY KEY ('id') made by require, require_once, require_once, require_once, include_once, ProSites->__construct, ProSites->install, dbDelta

Any thoughts on this? Is this an issue with Prosites, or something on my server?