With older tapes, there can be mechanical problems, from the magnetic coating deteriorating, or falling off, to "hub-bump," where indentations can form in the tape, from being stored partially rewound.
When working with older tapes, I Play them through completely once, and then Play them in reverse, rather than use the faster Rewind. This does contribute to a tiny bit of head wear, as the head is in contact with the tape, but the slower reverse speed does not stress the tape's backing, as much as Rewind, or FFW can. If there is still a problem with the tape, you might leave it in that reverse Play (now completely rewound) state for a few days, before you go to Capture.
If the problem still exists, then I would jog the tape a bit in the deck, to get past that, and start Capture from beyond that point.
Good luck,
Hunt
