It is very sad to write it but I have to do it anyway.
Bad news are that because of a failure on MySQL server in our hosting provider's datacenter GanttHive data were lost. They didn't have any monitoring or it didn't work, anyway the problem was detected more than 15 days after the failure. They keep backups only for 15 days, consequently, they had no data backups by the time when I detected the failure. I trusted them too much and didn't backup data on my own. As a result, GanttHive data is lost forever and can't be recovered :( Both me and the hosting provider are responsible for this incident. You know who I am, let me publish the provider's name: it is PeterHost, Russian hoster based in Saint-Petersburg. Think carefully if you decide to host your data there.
Well, good news are that we didn't have too sensible data in our database, and GanttHive itself was not very useful. I am working hard on a new GanttProject web site which, as I hope, will become much more valuable for our users. And of course it will be hosted on a more reliable hosting.