I'm not sure, but thought there is a download limit. Had it in the past too, but needed to wait 24 hours and I could downloaded it again.
Finally I donate money to Spesoft, for the fantasic free Pbx frontend, this forum, unlimited storage on ftp and gameexonline, so they can develop and get the site up and running.
Not saying that everybody should do it, but thats what I did to get unlimited downloads.