RandomAccessFile closeability.

[Paulo Levi]

Now, i'm pretty sure it is the second option (some shared state
somewhere in the library). I've searched google and the only problems
i can find are of the "same object" variety, and the problem appears
reliably (across computers) and it's definitely not the same object,
so it's probably some shared state in the library or my usage of it.

Sorry about the wasted cycles - i should have deduced this before asking.