54 test participants take test... only 49 show up in results!

I've been using Articulate Quizmaker 09 for the past week and am amazed at how easy it has been to use. I do have a problem, however that I need some expertise with. I've gone to Articulate Support and received an email back from them, but it doesn't address the one issue we have yet to resolve. We have recently designed a quiz for an up and coming company in the Mid-West. We are based in the Northwest in Seattle while they are back in Chicago. The initial test we had of the quiz content with them went well, and the responses we received were very favorable. But there were a number of respondents whose test results never made it to our Articulate Online server account where we were receiving the data. We were using the Guest Invite feature to record Name, Company, Start Date, etc. to allow them to log in to the quiz. For some reason the data never reached the share or showed up in the data. What is causing this? All respondents claim they hit the Finish button at the end of the quiz.

In our conversations with them, we have learned that they are on Macintosh computers and use a number of browsers, Firefox and Google Chrome being the most popular (which shouldn't be an issue). What I want to know is whether or not they have the latest Java or Flash Player updates installed may cause a problem if they are not installed. I already know the specs from Articulate and on the surface it covers all of the latest browsers we are concerned with. My feeling is that there is something inherent on their end that is the problem that has to do with a user maintaining their browser w/ updates, etc. (I know I get annoyed during the workday when pop ups come up to remind me of an update). I am looking for any variables from the other respondents.

Are you familiar with this problem? If not, could you put me in touch with someone who is familiar? I've yet to hear back from those 5 respondents as to which type of computer they were using. Also, if a person was using an iPad or other tablet to access the test, would that cause an issue? Just trying to cover all of the bases.

Respectfully,

Aaron W.