What was the worst bug you've ever solved ?
keeptrying: While I was working at Lucent, they had an builtin ftp client which was used to transfer images to the router from a server.Right after I checked in my code (a completely unrelated feature), this ftp facility broke such that you couldnt ftp an image to any router on any platform. So I was assigned this bug which basically stalled the release on every platform that we supported. (The CTO himself called me.)
Now you have to realise this BigCo supplies every cell phone carrier in the nation - Sprint, Verizon etc.What I found was that the ftp system had a bug such that if the image being ftp-ed was an exact multiple of 8k (or something like that) then it would fail. My checkin made the image file an exact multiple of 8K. (Story of my life!)I found the bug, emailed the CTO and he assigned someone from the core team to fix it. That guy calls me up and in the end I fixed it myself using vi and kibitz.