You can fire a correct error with this:

Try
  MySqlExec(myHandle, "Select * from Sometable", "MyCursor")
  RaiseEvent(this, "DataArrival", "MyCursor")
  If Used("MyCursor") OR SELECT('MyCursor')
    Select Count(*) From MyCursor Into Array aMyCount
    RaiseEvent(this, "DataArrivalCount", aMyCount)
    IF Used("MyCursor") OR SELECT('MyCursor')
        RaiseEvent("this", "AnotherEvent" )
        Select MyCursor   && THIS FIRE THE ERROR
           Scan
              ...       
           EndScan
    Endif
  Endif
  ...
Catch
...
EndTry

This code show the necessity of one logical contradiction:
* test for a alias, and if not exist select it for throw the exception !
This below logic makes me to say that it is a b..

Fabio