@Josh re: permalinks

Hi Josh, yesterday I posted a question about my error 404 page after submitting a comment. I changed the permalinks as advised, to “Post name” and it worked again. I tried today to submit an ad and added extra enhancements to it and I clicked on payment to use the admin callback and it refreshes the page and stays unpaid. The other problem is if I try to edit or delete the ad it goes to a 404 error page saying this is embarrasing message. Can you help?, Thx, H