Permission errors when trying to checkout a subversion repo on a CIFS share

"I had a similar problem with a CIFS share from my D-Link DNS 323. I tried playing with the various mount.cifs options (manpage) until hitting upon nounix which worked for me.

nounix: Disable the CIFS Unix Extensions for
this mount. This can be useful in
order to turn off multiple settings at
once. This includes POSIX acls, POSIX
locks, POSIX paths, symlink support
and retrieving uids/gids/mode from the
server. This can also be useful to
work around a bug in a server that
supports Unix Extensions.

So, in my case, my /etc/fstab now looks like this:

//192.168.100.101/Volume_1 /nas cifs rw,nounix,user=,password=,uid=1000,gid=1000 0 0

My problem wasn't quite the same as yours - I was making a fresh checkout of an svn repository to a new directory:

$ svn co example.com/project/trunk /nas/project
svn: Can't change perms of file '/nas/project/.svn/entries': Permission denied"