My wife and I each sit in a recliner to watch TV. We obtained two contour remotes. Both wirked for about 8 months until sonething wierd occurred? and they would not work, but for minimal reliability...
If you used different but functional manufacture codes to pair each remote, I could understand the interference. If they're transmitting the same code, it should still work as it had for the previous 8 months.
If you guys were playing "war" with the remotes, you probably jammed the IR receiver, if that could even happen. I'd power-cycle both the TV and cable box for a few minutes to clear any corrupt instruction, again, if that could even happen.
If that doesn't work, exchange the box and 1 remote. That's the benefit to rent...free replacements.