Several students have reported browser crashes when taking lessons. These appear to be mostly happening with Inernet Explorer for Windows 5.0 -- things definitely improve with 5.5, the latest version for Windows.
We've been tweaking the HTML that students see to heal this problem, but debugging different versions of IE is tricky. We believe the latest changes should help.
Students do not always tell us when they have problems. If you receive problem reports, please forward them to firstname.lastname@example.org.