hehe looks like i'm not alone with this!! (my post
viewtopic.php?f=3&t=1339)
1st you cant go back to previous version without losing all your download, not because they disappear but because they are incompatible with the old version. it has been like that for a long time now with shareaza.
as you said, the files aren't lost despite not showing on the download window. it just that they ain't saved as .sd files but .sav files. but if you delete the .sav so the file is .sd again and then you start shareaza, your download will be seen again in the download window