Dear Dave,
I think there is some plugins within CB not honour for the portable settings and so, still leave info in the application folder. You may try the following batch file settings. Most times it works for me, but sometimes not.
You need to create a batch file, e.g. codeblocks.bat, paste the following contents into the file and save it under the application folder of CB, the one with codeblocks.exe.
:: codeblocks.bat - begin
@ECHO OFF
setlocal
set USERPROFILE=%~dp0settings
mkdir "%USERPROFILE%"
:: :: For Vista or above
:: mkdir %USERPROFILE%\AppData
:: For Windows 2000 and XP
mkdir %USERPROFILE%\"Application Data"
START /D"%~dp0" codeblocks.exe %*
endlocal
:: codeblocks.bat - end
zac