The IAP routines have to set the controls by writing 0Bh to the FCNTL register using the timed access sequence. This process is described on page 23 and preceding sections of the datasheet, dated 06/08/05, though that's just the one to which I just referred. There are later datasheets, BTW.

I've found the Maxim/Dallas software tools to be a bit "lame" in that they barely do what their legends suggest, though some appear to be misleading. I wouldn't expect their app-notes to be any better.

Note that the datasheet points out:

"Only the upper bank of the on-chip program memory can be in-application programmed by the user software. The lower bank of the on-chip program memory contains system hardware-dependent codes that are crucial to system operation and should not be altered during in-application programming."

RE