Well, security is pretty tricky to get in Sharepoint...
I have several questions for you:
1. You usually open an InfoPath form via a document library. When you configure the doclib, you can specify that it opens in the browser. Try that? In that case, what happens to the users who have InfoPath installed? Does the form open in the browser or in InfoPath? It should never open in InfoPath.
2. Can you yourself navigate to the doclib?
3. Can you yourself open the form in the browser?
4. Do your users have sufficient permissions on sharepoint? Can they access the doclib? This could be your problem! See if they can access other document libraries (non-InfoPath ones).
5. It seems like you are doing Admin deployment. Try a simpler deployment where you deploy a simple from from InfoPath directly into a SharePoint document library. Does that work? Can you access the form? Can your users?
Hope you can get around your problems!
Dave.
David Airapetyan / Software Services ArchitectQdabra® Software / Streamline data gathering to turn process into knowledge