I know you said you may have moved the cord, but for anyone using Intermatic timers...(the ones with red "off" inserts and greenish "on" inserts)
I used to have the problem with my intermatic timers not always shutting off, especially as they get older. I guess the tabs on the on/off inserts get worn...? I found that if you double-up the inserts, (put two of the same color, side-by-side) it at least has it's back-up 15 minutes later.