Just a weird question; do you have your two cable boxes really close or in the same room? For example, your PVR is attached to your modem but you have a cable box to your TV across the room. Since the remotes are IR and not bluetooth; you could be controlling both boxes. So if, say, you click on your box - your PVR could be ordering everythings.
Are the unexpected recordings live or scheduled for the future?
I recall reading some posts here about similar situations. It's possible someone else's PVR is cross connected to your account at the TELUS back end.
I'm confused about the box you are calling PVR/modem. There is no such device. It's either a PVR or a modem, not both.
What is the model number of the device you are calling the PVR/modem that's not attached to a TV?