EDIT: I don't know what I did before but it seems to work ok now. I'm not seeng traffic form TortoiseHg but that's no major loss. Traffic from the browser is fine.
I've voted to close this question.
I'm behind an ISA server so I'm using CNTLM to purxy-auth clients like Git, Mercurial & even Chrome. I know Fiddler can do this too but CNTLM is much faster for Git, Hg etc. There are usually 2x 407's before the 200 goes through in Fiddler.
Fiddler ignores 127.0.0.* which is a bummer because that's where CNTLM is. How can I get it to capture this traffic?