Sigar - win 7 (64b) - Java7 - Intel

Hi, i'm new to sigar api and i try tu get a simpel MemInfo with using the Sigar API.
Im using Java7, Eclipse Indigo, Windows 7 (64Bit), Intel Processor.

So at first im adding the sigar,jar to the buildpath and coping the sigar-amd64-winnt.dll to the jre7/lib and to the project-root-container.

Then i only create a new sigar

Sigar sig = new Sigar();

but i only get an exception:

Failed to load sigar-amd64-winnt: java.lang.NullPointerException
org.hyperic.sigar.SigarException: Failed to load sigar-amd64-winnt: java.lang.NullPointerException
    at org.hyperic.sigar.Sigar.loadLibrary(Sigar.java:170)
    at org.hyperic.sigar.Sigar.<clinit>(Sigar.java:100)
    at Test.main(Test.java:10)

i already tryed, to load the native library by myself but unsuccessfully the exception is still standing.

so now my question, is it possible the sigar doenst work for intel x64?? or it doent matter?