Sky Television is beginning its process of upgrading all users to an online download system called On Demand and some customers receiving an updated decoder have run into difficulties.
Sky is upgrading 530,000 MySky HDi set-top boxes with its new On Demand feature this month and throughout the coming summer.
The new software will allow customers to download programmes from its collection of shows and watch at any time.
As part of the roll out 240,000 Sky Digital customers and owners of the first-generation MySky box would have their set-top boxes replaced with a new Sky box.
A spokeswoman for Sky said the full replacement plan would take up to 18 months to complete.
"Feedback is good or great," the spokeswoman said.
However, some customers had reported trouble with the replacement boxes.
One person reported to NZME they needed a technician to come and replace the box after it 'froze'.
Another person on technology forum Geekzone said they had the new Sky box installed and thought the new user interface was "great - makes the MySky in the other room look very dated".
"There are no widespread issues," the Sky spokeswoman said.
"As with change there have been some issues to work through, often when a customer has made changes themselves without our technician and that's what I believe these comments are."
Investors heard at a recent meeting that the upgrade to the new software for On Demand service will happen automatically for MySky customers, who won't have to do a thing.
Along with the ability to download previous episodes of TV shows available on channels the customer subscribes to, the interface will also be updated to appear in high definition.
In October, Sky raised the prospect of viewers switching off when the Rugby World Cup ends.
Chairman Peter Macourt told the company's annual meeting that Sky faced an 11 per cent fall in profits for the 2016 financial year.
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