You may also want to check/update your list of netloadmodule sites. I think loose-screws.com was the one that often produced that invalid zip file error. Currently I only have these two sites listed, but I think there's a new one. Perhaps someone will post it here.

*NetLoadModuleSite "http://www.loose-screws.com/download.php?netloadmodule=" ".zip"
*NetLoadModuleSite "http://www.ls-universe.info/download/modules/"