Just got an answer from a patent attorney. His response:

The short answer is maybe. The Markman, under certain circumstances, can be used in another case....though not always. There are a number of factors the court will consider in determining the effect of a prior Markman ruling ...

1.The issue raised in the current proceeding must be identical to the one decided in the first action;

2.That issue must have been actually litigated in the first action;

3.Resolution of that issue must have been essential to a final judgment or ruling in the first action; and

4.The plaintiff must have had a full and fair opportunity to litigate the issue in the first action.

Good luck to you, me, us, and all longs.