DLL not found in jar-based natives distribution, jcuda specifically

According to jcuda Downloads page

Since JCuda 0.8.0RC, the native libraries are contained in JAR files as well, and unpacked automatically when they are required. These JAR files have to be present in the CLASSPATH, together with the main JAR files.

I have added the directory-path containing the jcuda jar files to my classpath environmental variable. However, for the main program below I get the following error. For the main2 program it works fine. This is Kotlin rather than Java, but similar enough in this case. Code snippets adapted from tutorial examples. Any help is appreciated.

Exception in thread "main" java.lang.UnsatisfiedLinkError: Error while loading native library "JCudaDriver-0.9.2-windows-x86_64"

import jcuda.Pointer
import jcuda.driver.JCudaDriver
import jcuda.runtime.JCuda

fun main(args: Array<String>) { //error

fun main2(args: Array<String>) { //works fine
  val pointer = Pointer()
  JCuda.cudaMalloc(pointer, 4)
  println("Pointer: $pointer")