The former Version Inkscape 0.48 didn´t have this problem.
Copy to Clipboard from Graphpad Prism 6 Version you can choose WMF (+) or EMF (+) or the old WMF and EMF in the Preferences no one of these Settings have a function when you try to insert the Vector graphic from your clipboard in Inkscape Version 0.91 x86 and x64. Nothing will displayed.
The former Version Inkscape 0.48 didn´t have this problem.
Copy to Clipboard from Graphpad Prism 6 Version you can choose WMF (+) or EMF (+) or the old WMF and EMF in the Preferences no one of these Settings have a function when you try to insert the Vector graphic from your clipboard in Inkscape Version 0.91 x86 and x64. Nothing will displayed.