Cell counters - Beckman Coulter Z1 counter - (Sep/23/2014 )

Has anybody here had experience with this cell counter? If so have you ever seen the screen read "abnormal aperture flowrate"? 

Been having a problem with one of the counters recently. Also what standards have you guys found to be the best for this machine?

Regards,

Sean 

Sorry I know this is late and you have probably figured it out by now. Yes, this is an analysis error, It means.. the Aperture is blocked. To fix it you press "Unblock". If you have any other trouble there is a helpful Manuel that covers all the error messages and other technical difficulties: http://www.coulterflow.com/bciflow/documents/instruments/Z%20series/ZSeries%20Op%20Manual%20(9914591D).pdf