When having a working copy on a samba share, i used to get alot of “Failed to add ‘XXX’: object of the same name already already exists”. It seems that the problem lies on the samba configuration.

SVN tries to move a readonly file.

The reason why the file is created read only, i do not know. But setting this in the share section in smb.conf solved the issue.

force create mode = 0664

i have been told that this in the global section also will do the trick

delete readonly = yes