OVA import using importVapp fails for ISO files

I am using Java SDK to import OVA from local file system. I followed the sample code in vapp/OVFManagerImportLocalVApp.java

That works fine for VMDK images. Unfortunately my OVA also contains an ISO image (mapped to DVD drive). Upload of that file fails. It uploads 42k and then gets a server error. Neither PUT nor POST nor different content-types seem to make a difference.

Are there any examples or tricks to upload ISO files?

Thanks, Patrick