One of my Students had problems getting the toolwire scenarios to run. The whole intro would work but when it came to the lab it simply would not load.
The labs use a vpc activeX control which in his case did not run under the custom security settings he had in IE7. After adding the site to the Trusted Sites Zone AND resetting the trusted sites settings to its defaul level of medium, the lab excercicse loaded correctly.
Just a tip if you come across this particular problem with your students in future