I guess Mr. Fred is the founder of PureBasic. Well then, I think he is planning new features for PureBasic 4 for Linux and that's why he is so busy. Please remember, the more you put effort into development, the more accurate results you get.
I have seen many people (mainly administrators of software) who haven't shown up in their forums for a year. It came out that they were developing a new version of their software, and they showed up after a long while with an announcement of the new version; I guess the same happens here (but, hopefully, in shorter time).