I have received the iPads about two weeks ago, but could not start playing with the testing software until last Thursday.
Something went very iffy in my iPads, and the Q-interactive program refused to open: every time it logged me in and then immediately went to update itself, invariably crashing during the update.
Pearson were terrific in their client support, but nothing they tried worked. In the end, they took the iPads away, and it took them a few days to log in. They still didn't seem to know what went wrong in the first place.
This glitch is a concern, but it seems to have just hexed my iPads. I know that another person who is involved in the trial has been able to open and work the testing software.
In any case, if you have similar problems in using the software, don't assume you are doing anything wrong and get Pearson to work it out. Hopefully, by the end of the trial they will have the problem solved.
In the meantime, I'm madly playing with the software and will send updates shortly.