Incomplete checkout into empty directory, presence of nodes are 'server-excluded'

Hello!

Our colleagues use TortoiseSVN to checkout a subdirectory of a
repository into an empty target directory.

Sometimes this works perfect, but in the last time very often the
checkout finishes *without error message*s, telling it has completed,
but not all files were transferred to the target directory. Looking into
the SQLite database "wc.db" of the working copy, in the nodes-table we
find the missing files as entries with "server-excluded" in the column
"presence".

How can we track down the reason for the file being "server-excluded"?

Best

Jörg