P1 - Time offset changed for no good reason

[netmask]

Just had a call from a friend with a P1 and reported that all of the EPG times were one hour out. I then instructed him how to look in setup and he found the offset was set at +11.

At the end of last DST he adjusted it via phone instructions from me to +10 and has been recording many programs successfully since then. The last thing he recorded was a program last night on GEM.

I thought maybe time settings were on Automatic (from the stations) but no it's on network connected to Bigpond via cable modem.

I talked him through changing it to +10 and all times are now correct.

Any thoughts as to what could have happened?