cubase 5.5.3 autosave corrupt

Ive just transferred my cubase 5.5.3 on to my new imac had a few teething problems however after selecting a new project and using one of the template all goes well then after a few minutes I get a sign saying that autosave can save as the file is corrupt please save as another file…anyone help on this? Ive looked at the database but cant see anything

Well, that would mean, your project file is corrupt, not the autosave function…!?