pgf-3 breaks somehow latex-beamer see e.g. http://tex.stackexchange.com/questions/192633/why-is-beamerpstrickspreview-no-longer-compatible-now http://sourceforge.net/p/pgf/bugs/315/ To use latex-beamer with pstool is also impossible. Downgrade to 2.10 fixes the problem. Reproducible: Always
so... after some testing: pgf-3.0.0 seems to exhibit what you describe, 3.0.1 is ok, so let's close this!