+1  A: 

Is the silverlight app also on https? If not, you might be hitting a security wall which does not allow to intermix http and https application domains

ptor
Yes! it works, thank you so muchso the SL2 RTW rule is: cross-domain is allowed but NOT (cross-domain+cross-scheme)- to work on http://my-customer.com, my customer MUST use http://me-supplier.com/app.xap- to work on https://my-customer.com, my customer MUST use https://me-supplier.com/app.xap
JazBee
+1  A: 

I think the answers to this question may explain it.

Generally HTTPS doesn't like you drawing data between domains within a page because the certificate is tied to the current domain.

glenatron