Why doesn't SecurityChecker bring me to the vulnerable line of code when I double click on a vulnerability?
For some vulnerabilities, SecurityChecker is not able to determine the exact source line but only the file. Any vulnerabilities found with Run-Time analysis should take you to the specific source line.
Compile-time will take you to the first line of code within either the file, the type, or the method/property/indexer member depending on the closest location to the vulnerability.
Integrity does not have the information to go to a specific line. These tests deal with HTTP request/response messages and not the actual aspx page.