Full releases are generally a long way apart. Looking on snapfiles.com, it shows v4.5.3 was released in 2007 and 4.5.4 in 2009.
As stated above, the beta releases are fine to use. If you are concerned you might loose some functionality, simply take a copy of the files that are in the zip file you download for the update. -- <http://forum.pspad.com/read.php?2,53454,53551> PSPad freeware editor http://www.pspad.com
