Sylvio, Has this been reported to Linden Lab? Much of our educational content in SL is affected by this problem, and it is not practical to give visitors instructions to roll back their flash version. Gosh, it is hard enough to overcome the existing barriers to new user success withoug adding something like this!
I will post about it on the SLED list and see if any other educators have noticed the problem.
Best
Thynka