As of today (this will be committed after Yiannis has finished moving around a few directories),
autorevision will no longer support anything but Subversion version 1.3 and upwards.
Support for manually parsing the entries file has been abandoned alltogether, and autorevision now demands XML output from svn. XML output is not supported prior to Subversion 1.3.0.
If you do not have a recent enough svn client installed on your machine, you will of course still be able to compile Code::Blocks. However, the revision will show as "0" and the revision date will be empty.
Though this may be an inconvenience for some, it is something you have to live with. The never-ending issues with parsing human-readable, localised data in unknown encodings have become unbearable. XML should ensure that no such issues come up again in the future.
This comes at the price of requiring everybody to use a Subversion client that's not older than 11 months, which I think is an acceptable fee for avoiding all that grief.