I had InfoPath 2013 installed and ran into problems with the SaveToSharePointList, where it simply gave me the error "Couldn't save to List - https://..../_vti_bin/lists.asmx" (Office 365). It honestly scared me, so I quickly uninstalled Office 2013 and setup Office 2010 back to default, and it all worked fine again. Sorry I couldn't test it or help out, but this was in a production environment and we are using that command very extensively (probably never should have tried Office 2013 yet anyways!).