SQL Server 2000 does not log the procedures modified using ALTER statement. Here's the script to find out the same.
2009-07-06 (first published: 2009-03-02)
This script compares the code (SP, Func. etc.) between two databases (say Dev and QA) and reports the objects which have differences.
2009-02-26 (first published: 2007-03-08)