I just tested the line numbering on several large projects and one small one and it VBSourceTrace does not hang on any project. I am testing on Windows 7 64 bit.
You are using the current version so that is ok. There must be some issue on your machine. You say that the renumbering works on for you on Vista, is this the same project you are using in Windows 7?
Are you renumbering the whole project or just a few forms/modules/classes?
If you can get VBSourceTrace to consistently hang, would it be possible to test with your project.