I made some tests and I guess the problem is definetly related to package hyperref: \usepackage[bookmarks]{hyperref}
If I don't use it, and remove following code, no problem: \addcontentsline{toc}{chapter}{Indice} \listoffigures \addcontentsline{toc}{chapter}{Elenco delle figure} \listoftables \addcontentsline{toc}{chapter}{Elenco delle tabelle} I think there's something that messes up things with the algorithm stuff... Regards, Diego