I recently migrated a SharePoint Team site from our dev to our production environment (SP 2010 Enterprise). Now, whenever I create a workflow using SharePoint Designer, the initiation form generates as an ASPX file rather than an Infopath XSN file. So, whenever I try to manually run the worflow using the "Start" button, the form doesn't close after running the workflow. I checked to make sure the site collection features are the same. When I create a new list (not migrated), then create a workflow within it, the initiation form is also ASPX. However, if I create a subsite - then a list and workflow on that subsite - the initiation forms there show up as XSN. I've looked around on the forums and google, but can't find a way to force the forms to display as ASPX or to change them to XSN from ASPX. I can submit screenshots or any other details that might help figure out what's going on.

Does anyone have any ideas?

I have the exact opposite issue. I need the initiation page to be .ASPX but am forced to use InfoPath form. According to what I've been reading, the .aspx one is the default, but I can't find where one switches it over to .xsn so I can reverse it).