Using OpenID STS as Identity Provider

Question

Using the example described by Matias Woloski (http://blogs.southworks.net/mwoloski/2009/07/14/openid-ws-fed-protocol-transition-sts/), I've created a custom STS using WIF to authenticate users using OpenID.  This works fine as a stand-alone STS for relying parties, but I'd like to plug this into Geneva Server as an Identity Provider.  Doing so will allow users to use OpenID or another authentication method and will allow us to utilize Geneva Server's full capabilities.

The flow in this scenario will look like this: RP->Geneva STS->OpenID STS->OpenID Login->RP.  So far I've been able to get the redirection to the OpenID login to work, but after authentication occurs, the user isn't returned all the way back to the original relying party application.  Instead, they're just sent to the OpenID STS default page since it looks like the original "ReturnToUrl" isn't being preserved.

So a couple of questions: 1) Is this a valid scenario that Geneva should support (essentially it's a hop from STS to STS to STS)?  2) Am I missing something either in my configuration or my custom STS that would make this work?

Thanks for the help.