Lars have released Liferea 1.4.4 and state this release as a stable version, thus removing the 1.2.x version. Meanwhile, 1.4.5 is on the process of cooking right now and it will be out shortly (hopefully). This version also fixed nasty bug that appeared on 1.4.2b (and probably 1.4.2c) which could cause data loss. It's recommended that you upgrade to the latest version, 1.4.4 (for now). Check Liferea Blog for more detail information.