The issue occurs in almost every session that I teach using WizIQ, and seems to occur independently of whether the student is using a Mac (as am I), or a Windows system. This is why in my tutoring work, whenever possible, I prefer to use Coccinella (a Jabber-based whiteboard which behaves considerably more robustly) than WizIQ.
I haven't attended enough classes to be able to comment on the frequency of the problems with attending. I haven't noticed any of these problems in playing back the recorded classes, by the way.
I just updated to the latest Flash Player (on Marian Heddesheimer's suggestion), but that seems to be version 10,0,42,34. Are you suggesting that I just made matters worse and should try to go back to 10,0,22,87? I am not sure my present WizIQ student, assuming that his Mac is kept up to date, would go for a downgrade on his Mac.