Adwords Source not showing correctly in SalesIQ

Adwords Source not showing correctly in SalesIQ

We have experienced that in some cases SalesIQ shows Adwords directed traffic as "Direct"! 
We can see that the links captured for the actions do have a gclid adresses, but SalesIQ does not categorize the visitor as coming from Adwords. 
This messes up our analysis of the sources.
Please explain if we are missing a setup?
How do you determine if the visitor is Adwords or Direct?