I've recently been receiving emails triggered by updates on SF.net tracker items I commented on ages ago. As these are annoying, I tried to turn them off. At the bottom of these notification emails, it says:
To unsubscribe from further messages, please visit https://sourceforge.net/auth/subscriptions/
Doing this, I am first asked to login (makes sense). After having logged in, though, the page simply gives me an error 500. Reproducibly, on different days.
In case you think it matters: I reproduced this on my Mac OS X 10.8.5 machine, using Firefox 26, Chrome 32 and Safari 6.1.1