Sorry Michael, I just heard back from my client and even though they can use the wysiwyg field in firefox, saving the post doesn't save the wysiwyg field data. So it looks like I will be trying the temp fix suggested above by Peter.
Hi Michael, I imagine Peter means that you overwrite the wysiwyg.js file with the contents in the github commit. I haven't tried replacing the wysiwyg.js file with the new code yet as my client was fine with using Firefox (works fine in FF or Safari by the way) and I'll probably wait until the next plugin update release.
