The indexer doesn't properly index words that are numbers anymore in Binky.
The problem is fixed in the development version of DokuWiki. You can either manually apply the changes in inc/indexer.php from
https://github.com/splitbrain/dokuwiki/commit/5a1d05488ca6e176af4d195accbdca8010cf3416#diff-0f5e4a44dc65589a0ebaf00eff4c7dddR218 or simply download and replace the changed file inc/indexer.php:
https://raw.github.com/splitbrain/dokuwiki/5a1d05488ca6e176af4d195accbdca8010cf3416/inc/indexer.php in your installation, this is identical to the file in the Binky release just with the fix.