queXF 1.12.1 has been released today on Sourceforge
queXF 1.12.1 fixes a bug in the new ICR feature where during recognition, the thinning function failed due to a quirk in PHP global handling. ICR should be more accurate after applying this fix.
To upgrade:
1. Backup config.inc.php (copy to config.inc.php.bak)
2. Extract the new package over your existing installation of queXF 1.12.0
3. Copy your config.inc.php.bak file over the extracted config file