GC being too eager?

[Paulo Pinto]

In a toy project I am working on with D v2.065, I came to the 
following situation:

Node path = solver.find (map, start, end);
if (path !is null) {
    path.writeContents();  <-- Access Violation
}
Apparently between the test and trying to use the class, the 
reference becomes null.

Quite strange in a single threaded application.

Any idea what might be happening or should I delve into assembly?

--
Paulo