We just currently put up the fixed ALLBRAD.CBX - check it out!
www.ni.com/support > Drivers and Updates > Search Drivers and Updates > type 'Lookout 5' and you should get the link for 'Lookout 5.0 for Windows -- Fixes'
Hope this helps
Roland
PS: You should be able to use the driver CBX version 5.0 in Lookout 4.5.1. Or you might consider to upgrade to Lookout 5.0. www.ni.com/lookout.