Did you also make sure the svn.exe being used by Code::Blocks is the same base version?
If TortoiseSVN is 1.5 then the svn.exe must also be 1.5.
If TortoiseSVN is 1.4 then the svn.exe must also be 1.4 for both to work with Code::Blocks svn folders/files.
Edit: The change was 1.4 to 1.5 was a very major change from an user side file structure so an user must only use 1.4 or 1.5 on the local SVN folders. TortoiseSVN upgrades the SVN folders to 1.5 format so all 1.4 svn clients fails to work on them.
Mine works OK on Windows XP SP3.
TortoiseSVN 1.5.0, Build 13464 - 32 Bit -dev, 2008/07/11 18:30:08
CollabNet Subversion svn, version 1.5.0 (r31699)
Tim S