This release mostly works around breakage caused by AVG Security Toolbar 14.0.3.* extension, it prevented Adblock Plus from working correctly among other things.
Detailed changelog: The following lists the changes compared to Adblock Plus 2.2.3. If you experience issues with this release please check the the list of known issues. • Worked around AVG Security Toolbar 14.0.3.* breaking Adblock Plus among other things. • Made sure that first-run page always opens is the current browser window (bug 819561).