Hello, 
I have the same problem. We are using the trial version and we had lots of complaints that they cannot record their voice because the stop button doesn't work after pressing record in voki classroom.

This would be because of the flash player,as you have hinted above, but the thing is I recorded my voice maybe three times last week but when I opened it today in classroom with the same laptop, I had the same problem as well. It eas turning and turning but non functional..

What do you advise us to do? I am thinking of extending the membership but if we will continue having such problems, it really takes a lot of time to fix it for us teachers who really have limited time left for these kind of fun activities. 

Thanks..

Thanks for your answer. However, the message that my bank sent clearly states that I was actually charged, not like the earlier authorization check transactions I did before. That's why I was anxious.
Most probably I will keep using Voki after the trial ends. But I am not sure I will be charged once more, if these pending transactions are not refunded.

Thanks
Sule