Strange / erratic behavior in CreatePivotTable ()

I am writing VBA code to automate some processes in Excel and I come across very strange behavior for which I could not find any documentation / help.

I have a procedure MAJ_GF

that first executes a function GF.Update

, checks the result, and then runs the procedure GF.Build

(which basically takes data received with help GF.Update

from different sheets and does a bunch of things with that).

At some point this "group of things" requires a pivot table, so it GF.Build

contains the following line:

Set pvt = ThisWorkbook.PivotCaches.Create(xlDatabase, _
   "'source_GF'!R1C1:R" & j & "C" & k).CreatePivotTable("'TCD_GF'!R4C1", "GFTCD1")

      

        
        
        
      

    

Strange behavior:

• when i run MAJ_GF
  
  VBA executes correctly GF.Update
  
  , then starts GF.Build
  
  and stops at the above line complaining about "Bad argument or procedure call"
• when i start manually GF.Update
  
  then start manually GF.Build
  
  everything goes smoothly and GF.Build
  
  does what it is supposed to do from start to finish, no error
• even stranger, when I set a breakpoint on the incriminated line, run MAJ_GF
  
  , then VBA pauses on the line as expected, and when I say Continue ... it just continues smoothly and without errors!

I've spun this around and around, double-checked the value of each variable and it just doesn't make sense.

Anyone ideas?