SVN do unnecessary chmod on .svn/tempfiles

Question

My working dir is on an TrueCrypt NTFS volume, with umask 000. So I can read/write on any files with no problem.

But I can't do svn command on it, for example `svn update' shows error:

svn: Can't set permissions on '.svn/tempfile.8.tmp':

strace svn up gives:

...
chmod("sbin/.svn/tempfile.2.tmp", 0770) = -1 EPERM (Operation not permitted)
fcntl64(3, F_GETFL)                     = 0x2 (flags O_RDWR)
fcntl64(3, F_SETFL, O_RDWR|O_NONBLOCK)  = 0
write(3, "( failure ( ( 1 76:Can't set per"..., 172) = 172
fcntl64(3, F_GETFL)                     = 0x802 (flags O_RDWR|O_NONBLOCK)
fcntl64(3, F_SETFL, O_RDWR)             = 0
read(3, "( abort-edit ( ) ) ( failure ( ("..., 4096) = 191
gettimeofday({1276661368, 382789}, NULL) = 0
lstat64("sbin", {st_mode=S_IFDIR|0770, st_size=0, ...}) = 0
select(0, NULL, NULL, NULL, {0, 1000})  = 0 (Timeout)
write(2, "svn: Can't set permissions on 's"..., 82svn: Can't set permissions on     'sbin/.svn/tempfile.2.tmp': Operation not permitted) = 82
close(3)                                = 0

So, the error occurred when svn chmod on some tmp files. But this is disallowed in the TrueCrypt volumes, and it's just unnecessary.

Can I bypass the chmod lib calls when launch svn on TrueCrypt volumes?