Here are some articles that deal with the use of “debug=true” in the web.config file.

http://weblogs.asp.net/scottgu/archive/2006/04/11/Don_1920_t-run-production-ASP.NET-Applications-with-debug_3D001D20_true_1D20_-enabled.aspx

http://blogs.msdn.com/tess/archive/2006/04/13/575364.aspx