[dba-VB] Trapping Errors When Trying To Get Distance Using MapPoint 2006

To all,

I have just started a VB6 app that using MapPoint 2006 to calculate a few
driving distances when required.  The actual driving distance calculator is
in a function, on which I have put some very simple error trapping.  However
when I pass a postcode (in one case B18 2PX) I get the error message (which
bypasses my error trapping) as below:

Run-time error '-2147181454 (80049c72)':
The requested member of the collection does not exist.  Use a valid name or
index number.

This is one of a few it errors on, all others work fine, but has anyone any
idea why this isn't being picked up by my error trapping:

Function GetDrivingDistance()
On Error Goto MileageCalcError
      drivingdistancecode

ResumeOnErrorHere
      savemap
      exitmappointapplication

Exit Function
MileageCalcError:
      Resume ResumeOnErrorHere
End Function
Thanks in advance for any help on this .....

-- 
Paul Hartland
paul.hartland at googlemail.com