The player hasn't changed in the last two years ...
The problem with misbehavior is caused by incompatibilities between the server java environment and the client one.
I've had odd problems trying to run courses when hosting the site on my OS/X laptop, problems that mostly disappear when I host the site on Linux, for instance.
Going to a javascript player in the medium-term seems like a good solution to me. Java just flat-out sucks.