The relative path is "src\alogg\src\alogg.c". At first I wondered if having two like-named folders in that path was confusing CodeBlocks, but the IDE has no problem with another source file at "src\minibpm-1.0\src\MiniBpm.cpp".
The revisions from this forum's Nightly Builds subforum are:
11-10-12 (Nov 10, 2012) r8549
11-23-12 (Nov 23, 2012) r8598
4-12-13 (Apr 12, 2013) r8982
8-6-13 (Aug 6, 2013) r9246
11-16-13 (Nov 16, 2013) r9455
And 12.11 stable is r8629.
Windows XP Pro x64, US English locale, non Unicode programs use Japanese language. That last setting usually has little effect besides causing backslashes to display as the Yen symbol, and wouldn't explain why some builds of Codeblocks display the file while others don't.