Does this seem like a possible answer to your situation?
(from http://www.uwplatt.edu/csse/tools/subversion/subversion-help.html)
“Failed to add file ‘(name here)’: object of the same name already
exists.or
“Can’t open file ‘folder.svn\tmp\text-base\file.svn-base’:
The system cannot find the file
specified.”Both mean that two files in the same
folder have the same name except for
capitalization; for example
“Readme.txt” and “README.TXT”. Unix
and Subversion are case-sensitive, so
the files are considered to be
completely unrelated. But in Windows
is not case-sensitive, so when it
tries to update README.TXT on top of
Readme.txt (say), it breaks.The surest way to fix the problem is
to log in to a Unix system (such as
io.uwplatt.edu) and use the unix notes
to check out the repository there. You
can then use the svn mv command to
rename one of the files. If you are in
the middle of trying to add a file to
your repository, you might try using
TortoiseSVN->Rename… to rename the
existing file to something entirely
different and then updating. Note that
you need to use the TortoiseSVN rename
commands; merely renaming the file in
Windows Explorer won’t fix your
problems.
I had this same error, and using Tortoise SVN’s repo browser was able to confirm that there were two files in the repository with the same name only varying by upper/lowercase letters. You can also fix this issue through the repo browser by deleting one of the files (you can do a diff first through repo browser to make sure you have what you need).