Hi macado,
this sounds like an old problem.
One of your action before the software distribution is the installation of the LANDesk agent I think. You have to be sure that this agent didn't start the policy sync, vulscan and inventoryscan because these things can interrupt the software distribution in provisioning.
For that reason we configure a very small agent with only software distribution and set the policy sync to start in year 3000. The last action in our template is then to install the "true" agent.
Hope that helps.
Kind Regards
Christian