[texworks] TeXworks pdf viewer does not reproduce imbedded pdf graphics correctly

[Peter Hertel]

I use texworks.exe as provided by the MiKTeX 2.8 distribution on Windows 
Vista. If I include a PDF picture, as generated by epstopdf.exe, into my 
document (\usepackage[pdftex]{graphicx}), it will not be display 
correctly by the TeXworks PDF viewer, the numbers on the coordinate axes 
are missing. However, Acrobate displays what should be there. Is this a 
known, a solved or a new bug?
Peter