[Plugin: WordPress Mobile Pack] WordPress 3.4.2 breaks mobile detection

I upgraded Mobile Pack to version 1.2.5 and everything works fine. But when I upgrade WordPress to 3.4.2, on mobile devices I am no longer seeing my mobile theme. I reverted my WP installation back to 3.4.1 and everything works fine on mobile devices again. Any help would be appreciated. Thanks!

http://ww.wp.xz.cn/extend/plugins/wordpress-mobile-pack/