Hi Dan. This sounds like an IIS problem of some kind. Make sure there's not multiple SmarterTrack sites pointed at the same application pool.
If that's not the case, look in the Event Viewer under Windows Logs >> Application. Filter the current log to only show Critical and Errors messages. Look for any ASP.NET or Application Errors that may point towards what's happening.
After this, I would recommend a support ticket so that we can get on and take a further look into what's occurring. I hope this helps.