Curious problem I've never come across before. Consider the code below (an example as a very similar error occured in a similar piece):

Select *, RTE_NO + GEN + DIRECTN + STR( ESU_ID, 11) ;
  from mclMPSer!ROUTE_ESU ;
  where RTE_NO + GEN + DIRECTN + STR( ESU_ID, 11) not in ;
    (  Select Rte_No + Gen + Directn + STR( ESU_ID, 11) ;
  	from RouteESUMap) ;
  into Cursor csrNewRESUs NOFILTER 

lnRecCount  = _TALLY
If lnRecCount > 0					&& then new ROUTE_ESUs to copy over 
    Wait WINDOW "Updating GIS RouteESUMap table with new Route-ESUs from mPlan ..." NOWAIT NOCLEAR 
    Select csrNewRESUs 
    ...

When it gets to the line If lnRecCount > 0 it crashes with the old:

"operator/operand type mismatch" error.

So I halt it and inspect in debug. I find, of course, _TALLY is 0 or an integer (depending on which example), but lnRecCount is .F. How can this be when the previous line has equated lnRecCount with _Tally!!! ?

Now the first time it happened, I thought it a strange anomoly, and I equated the 2 values in the command window. Then I let the form run on, and the code below it worked OK, but it did exactly the same at the above code.

'ppreciate it

Terry