There is a doctrine in patent law called the "doctrine of equivalents." [1] In short, it limits the ways you can use obvious work-arounds. In practice, it's very complex because there are often good reasons why they specified an "incrementing" counter rather than "any counter," but the idea is that you can't make a trivial change to get around the bulk of a patent.*

[1] http://en.wikipedia.org/wiki/Doctrine_of_equivalents

* I am not your lawyer, get a lawyer, etc.