Published InfoPath Form Not Appearing in SharePoint

Mercedes,

In the IP form, in the form settings, if you go to the Compatibility category and check if it is set for Web Browser form?  And when you walked through the publish wizard, you checked the box allow this form to be filled out on the web?  When it doesn't work, do you mean if you go to your library and say new document, what happens?  It doesn't open your web form?  It should have updated the content type in the library with the form template, and show the IP icon on the new dropdown. 

I just tested this by creating a form library, opening IP Designer and creating a library form, creating submit data connection and publishing to the forms library.  It opens fine in the browser.  And no I don't believe it should take 24 hours to show.  It sounds like it's not getting fully wired into the content type of the library, or the form isn't truly a web form.