You would need to re run guided setup for it to work on that "other" cable, as well as remove the cable cards, if you haven't yet. The same goes when you move back home, and have the cards re-paired.
Series 2 (80 hrs,PLS, Retired)
TiVo HD 1TB (157 HD Hrs, PLS, "S3HD")
Roamio, Oh Roamio!
The TiVo Apocalypse begins on Sat 2013 Feb 16 00:00 GMT!