Excuse me, just after sending it realize that the best would be:

=CursorSetProp("Buffering",5,"Customer")
Begin Transaction
Insert into Customer (Fields) values (Values)
if TableUpdate(.T.,.T.,"Customer")
   End Transaction
else
   Rollback
endif

That way you revert the transaction if something fails. Actually, if TableUpdate fails, the correct thing should be to call some routine that tries to determine why and inform about it some way or raise an error to a higher level object/program.

Hope this helps.