Without looking further into your individual submissions I can't provide comment other than we do provide plenty of detection for both adobe vulnerabilities and for infected .pdf files.
When you submit files to us do you also contact support to raise a service request? If you are not doing so I would strongly recommend that you do, as then support can escalate your submissions to McAfee Labs.
Marking as 'assumed answered' due to age of thread. If you need any further assistance please don't hesitate to let us know.