I have been slow to get some old capturing done....doing a hell of a lot of it these days, and that goes back to about 2003 when I purchased my first DV camera which was a Sony TRV-250. I play back and capture using a Sony TRV-260 and there is no problems so far. All my critical tapes are stored in card plastic cases and kept in a box.
On an occasion I have re-recorded over old stuff, but usually within a few months of the original shots. I did this the other day, but with a tape about a year old (shot an apartment fire over old shots of my dogs, which I captured already). No visible problems, drop out or otherwise.
I would say for the cost of a tape, I wouldn't try to re-record over something so old. I do believe like Dan said, tapes have a limited time to them. However, it you are just shooting goofy stuff, or what I call document shots (street signs, highways signs, vehicle odometer, with self commentary for logging purposes for example) no big deal. But when it comes to the "money shots" you have to be kinda strict with your tapes. Once I shot a fantastic scene....a tornado, hurricane conditions, etc. I take that tape and lock it right out of the camera. I make a habit to never unlock a tape. But as mentioned, I did do it a few times.
