Backup failed - error : DataAccessException

Hi,

I try several times and I cant' succed to backup my data (It's my first attempt to do this, after I suscribe to Business Pack)

I get this error message :

com.adventnet.persistence.DataAccessException

Any idea of what's happenning ?

A few days ago, I had a problem on a form in my apps, and now I can't either edit or delete it. Is there any relation ... ?

Philippe