WIreportserver service keeps using more and more RAM until OOM

Hello,

Our BO server (sbop4.1 SP10) crashed a couple of days ago due to out of memory problem.  After restarting the machine, it's back to normal service. But I'm see the WIReportServer.exe is using more and more RAM while CPU usage is almost 0%.  In the logging file, I see more trace files, and one of centralMangementserver_trace file keeps complaining: "CSessionMgr::ValidateApplicationCUID: Attempt to login when specifying an invalid application CUID session. "  Can anybody tell me what it means, or how to track root cause?

Thanks very much!