If you are running SCORM Engine with SQL Server Express, you may run into javascript errors when you have a lot of traffic on the site.  We have a client that

encountered this and it was fixed by upgrading their SQL Express to SQL Server 2005.  It turned out that SQL Express only allowas for 2GB of RAM to be used and 1 processor core.  When they upgraded to SQL Server 2005, the server was allowed to use all 8GB of its Ram and all 4 of its processors.