I found this knowledgebase article http://digital.ni.com/public.nsf/allkb/814FEF952915137686257B6B006C5F4F?OpenDocument
I ran the Disable NSP batch file, and that seems to fix the problem.
Not sure if LabVIEW 2013 works without running the batch file, I can't remember which order I installed things in.
Nice to see there is an official fix for this now, will start using this in future, we have been using the workaround method johannseehauser posted earlier in this thread to rectify the problem up until now.
The problem does still seem to occur using labview 2013 but not seen it occuring on windows 8 so far, just windows 7.