defaulting site for non-managed goods

SUGGESTED

I'm having an issue as the product-site is not defaulting on the PO line but rather it is defaulting the financial site.  I have a specific site linked to items that are not-managed (for reporting purposes) but for some reason the site is not being defaulted on the PO line.  It defaults the financial site and when use the selection the site I want isn't displayed.  I can manually add the site but I want this to be automatic so users to not leave the financial site.  Any ideas?  

thanks

Christine