InfoPath Dev

I have a broswer enabled form that uses UDC connections on my Sharepoint site as secondary data connections. These connections pull data from Dynamics and populate drop down lists. Why is it that the fail to connect to the data source in the browser version, but work properly when opening the form in the client application? Are there some configuration settings that I am missing? I've been struggling with this for weeks now, and would greatly appreciate any insight into the matter.

Did you approve the UDC files in the Data Connection library?

I did approve the UDC files. Is it possible I could be having an issue with Double Hop? Is there a way around the double hop problem without configuring and using SSO?

I would think it's definitely a double-hop issue, since it only errors in the browser-form.  When you browser-enable the form, that introduces another hop in the data sequencing.  I've had this before where I was using a browser-enabled form to submit/read data to/from a database via a web service using a UDCX data connection file.  It only worked when I configured SSO and modified the UDC file manually to allow for permissions to be passed through.