Plugins in Custom Update Center appear as "Signed but not Trusted"

I recently acquired a Code Signing Certificate from Comodo for use with my NetBeans RCP Application. Signing the installer app.exe was fairly painless and incorporated into my Ant Build.xml script.

I wasn't able to figure out how to get NetBeans to utilize a tsaurl while signing all the nmb's in my app; but I did get my nbm's signed using my code signing certificate. I verified this with jarsigner and also looked into the manifest of the nbm's and found the required *.RSA file there.

When my users download the updates, they are presented with a Dialog listing all the nbm's and state that they are signed but not trusted. Is there another step I am missing or hints of what to check next? I'd like to have them trusted, as that is why I acquired the certificate.

I did resign the nmb's manually using jarsigner again to force the tsurl to be applied. This had no effect on the results. FYI