broken links and SERPS position

[kina]

I have seen several example now so it seems that broken external links do not penalise a site. I think this is wrong. I have seen sites which are based on a list of external links but of which many are broken and obviously haven't been checked for ages, well over a year at a guess. If ever there was a valid case for a penalty, this is it. One of these sites is at number 1 for a competitive keyword on both Google and Yahoo.