Koen,

There are a few things that can cause this:

Go to www.ibm.com.  In the search area enter the following:

   +"This database is currently being used by someone else" +backup

You will find some KB articles that discuss possible causes
and solutions to those problems.

Thanks,

Del

----------------------------------------------------

> Or notes backup fails and as gratitude TDP it gives me very limited
output.
>
> The output:
>
> Backup of Victor\Standards.nsf failed.
> This database is currently being used by someone else.  In order to
share a
> Notes database, all users must use a Domino Server instead of a File
Server.
> Backing up database Victor\Victor.nsf, 504 of 504.
>