Have you tried the onboard examples, http://search.ni.com/query.html?col=alldocs&layout=Example&qp=ContentType:Example&qt=onboard+7344+labview, do they behave the same.
The following KB, http://digital.ni.com/public.nsf/websearch/AC05B6F401633E6F862568080049A06D?OpenDocument, talks about which VIs can execute onboard and which VIs can only execute on the host?