I was having this problem and found that I had to change the Custom Permalink Structure.
Go to Settings->Permalinks
Custom Structure was checked and I had it set to
/%postname%
I changed it to
/index.php/%postname%
This seemed to do the trick, not ideal as it has index.php in all the url, but better than just the post id. I haven’t a chance to figure out why it did the trick, but glad it did.
