Hi I think I have found the issue - it has to do with this commit
commit 930e59dd3142a4ceba46826183e13d67b420e3de Author: Iain Patterson <w...@iain.cx> Date: Fri Oct 26 11:40:55 2012 -0700 Partially support _NET_WM_STRUT_PARTIAL. .... I run gkrellm and didn't realize that it was set to be a dock (see attached). So wmaker was trying to keep the maximized windows clear of my gkrellm instance --- very kind. Once I unticked the option in gkrellm everything went back to normal. My sincere apologies for leading you astray. B.T.W I have applied Amadeusz Sławiński's patch from 22/09/2014 16:53, and everything behaves as I expect. Regards, Johann