You would need a switch that supports multicast for the TV box to continue functioning properly. Telus installers use a gigabit switch from ZyXel but they are about to roll out a new switch by a different company. If your install was recent and you have the business card of the tech who did it I would give them a shout and see if they can drop one off for you. Otherwise you'll have to get your own as calling in to Telus to request this will most likely result in a billable dispatch.
I have one of the Zyxel switches. I've had zero issues since it was installed behind my PVR. My old Linksys switch couldn't handle things and started malfunctioning after a number of months.