all links broken when use permalinks

I’m sorry if one might think this is a re-post, but I’ve not found a solution to my problem from the other posts.

I’ve been asked to look into a problem for a friend. Here’s the situation.

1. I’ve got a fairly new blog https://yellowstonerivercouncil.org/news/.
2. It’s using the default theme.
3. It’s using the most recent WordPress version 2.9.2.
3. It uses permalinks and apparently these were working for a couple of weeks.
4. Now suddenly all of the internal links are not working for no apparent reason.
5. When I revert to the default links, everything works fine.

What would cause these to just break?

This is what I’ve tried.
1. I’ve looked for hack symptoms as suggested in another post, and found none.
2. I’ve created an .htaccess file with the snippet of code provided on the permalinks page and uploaded it to the wordpress-content directory. (there didn’t appear to be one before and did not seem to be a hidden file)

I still cannot get these links to recognize the appropriate page.

Any suggestions/advice would be greatly appreciated.

PS
I’m not sure if this is relevant, but this problem was discovered because we were trying to set up a feed of the blog on another web site and https://yellowstonerivercouncil.org/news/feed/ could not be found. However, when I revert back to the default (not permalinks) this still can’t be found.