up to a couple of months ago I would have agreed with you about the
system falling over with regular monotony - could almost guarantee
that at 6:50 pm the TV cable connection would fail (if I'd known
TV2 were going to do a complete re-rerun of Friends maybe I
wouldn't have got so annoyed

).
Having phoned Telstra for the nth time they did say they were in
the midst of upgrading the whole network (no further details) and
were experiencing problems.
They now seem to be sorted as far as I am concerned (tempting fate
here) and have not had a failure for at least 4 weeks.
They are advertising a big re-launch in ?November, so maybe they
are gearing up the system for that?
a couple of tales of failure in the early days;
the feed to the Kapiti Coast comes over the Paekak Hill Road - one
weekend a keen farmer managed to blast a hole in the cable when out
shooting; blacked out the whole of the Kapiti Coast. Saturn (as it
used to be) then trenched the cable rather than just running it
alongside the road - that's the cable beneath the tarmac strip you
can see in the road.
Second time the whole network blanked out was during a southerly in
Wellington - the above ground cable in Miramar was oscillating in
the wind at exactly the same frequency as the signal it was
carrying and this amplified transmission swamped and shut down the
whole system.
Didn't allow for that, did they?
The loose cable strung between lamp posts in Miramar was tensioned
up as a result.