It would appear that deploying an Infopath forms process causes Infopath forms to use the Infopath client, and disregard any previous settings in the form and the form library - after deployment of the process, you cannot stop the thick client from launching.
Example...
1. Create new Infopath form, and publish it to a basic SharePoint site with a Forms library. The form is set to use the web version, and the library is set to use the web version.
2. Try using the form, and it launches the web version.
3. Create a K2 blackpoint Infopath process, with the form from the library as the start action. Make it do something simple like create a task in a task list having the same name as a text field on the form.
4. Deploy the process
5. Go back to the form library, and launch a new form. Bang. The Infopath application opens.
If you now check the form library, it will have reverted to using the thick client. Setting it back to "web" will make no difference.
Any ideas ?