trouble with double sync

[ursulab]

Hi,

I have a little bit complicated configuration:
1. I sync
D:\A
with
X:\B\A.
X: is a virtual device, encrypted by Boxcryptor, i.e. the encrypted files are emulated so that they look like and can be handled as normal files.
The storage location of X:\B is D:\B\A. If you look at D:\B\A, all files are encrypted and have the ending .bc

2. I sync
D:\B\A, i.e. the encrypted files
with a webdav device (webdav[...] is here an abbrevitation for the real name)
\\webdav[...]\A

Wenn I run Sync 1, then Sync 2 and again Sync 1, Sync 1 reports an error that

X:\B\A\sync.f268.ffs_tmp cannot be moved to X:\B\A\sync.ffs_db
In German: Fehlercode 183: Eine Datei kann nicht erstellt werden, wenn sie bereits vorhanden ist. [MoveFileEx]
English translation: Error code 183: A file can not be created if it already exists. [MoveFileEx]

When I press "repeat" in the error message box, then it resumes and continues without an error.
Also, if I delete the file X:\B\A\sync.ffs_db before starting Sync 1, no error is reported.

If I run Sync 1 twice in a row without Sync 2 in between, no error occurs.


What I found out:
There are two files in D:\B\A\:
sync.ffs_db.bc (from Sync 1) and sync.ffs_db (from Sync 2).
If you look at X: there is only one file X:\B\A\sync.ffs_db.

So, the above error probably occurs because X:\B\A\sync.ffs_db references two files - and probably the newest.

My question is now if whether it is possible to configure FreeFileSync to use a name other than sync.ffs_db for its database?
If not, the only way I can think of is to rename the file D:\B\A\sync.ffs_db (from Sync 2) before starting Sync 1 and rename it again afterwards. I suspect deleting X:\B\A\sync.ffs_db, as I tried as first solution, is not so useful as it would slow down FreeFileSync or make the synchronization not optimal?

For help, I would be grateful.
Other solutions are welcome!

Thanks,
Ursula

P.S.: Syncronizing D:\A directly with a Boxcryptor encrypted \\webdav[...]\A is very very slow, so that this is no solution.