Andy,


From the help file on TableUpdate

Note If an error other than a simple commit error occurs while updating records, the first element of cErrorArray will contain –1 and you can then use AERROR( ) to determine the why the changes could not be committed.


Now try this code

IF NOT TableUpdate(2, .T., laALIAS, aSaveErrors)
   * force changes on all rows, but just in case, track
   * any errors in an array
   * You'll want something a little more sophisticated here.
   set step on (my code so I could see the results)
   WAIT WINDOW "Unexpected problem with " + ;
	    ALEN(aSaveErrors,1) + " records"
   AERROR(laErrorData)
   DISPLAY MEMORY LIKE laError*
ENDIF

And examine the information in the laErrorData array.