I have been using the SSL Server Test to see if various vendors that we use are vulnerable to the Heartbleed attack. But I need help with interpreting some of the results. Many of the domains that I entered resulted with an SSL Report containing a Summary giving an overall rating and stating that "This server is not vulnerable to the Heartbleed attack." However some of the results provide only the Server, Domain, Test Time, and Grade. So am I to assume that these servers ARE vulnerable since the report is silent to the Heartbleed issue?