Memory leak using AssetBundles

Hello,
I have encountered a memory leak on assetbundle load. After download a bundle using WWW, I save it on disk and then loading, using this code:

AssetBundleCreateRequest assetBundleCreateRequest = AssetBundle.LoadFromFileAsync(path);
yield return assetBundleCreateRequest;
assetBundle = assetBundleCreateRequest.assetBundle;

And then just unloading bundle

assetBundle.Unload(true);
assetBundle = null;
Resources.UnloadUnusedAssets ();

After memory from bundle is released we have extra 0.5mb added. This happen every time I load and unload assebundle, so memory grows until app crashes. This assetbundle was created with ChunkBasedCompression option. And no matter what bundle size,it always add about 0.5mb after unload. I have tested it with 100 kb, and 5 mb aseetbundle.
I have tested it on windows phone and ios device, so it’s not platform specific. Have anybody else can confirm this bug. Should I submit a bug report? It’s easy reproducable. Here is a profiler screenshots
Before :

After:

Yes, please submit a bug with repro project attached, much appreciated.

Bug reported yesterday but no any confirmation yet. Case number 756909

Thanks!