For some reason, when I upgraded my WP to 2.6, the forum index stopped showing -

http://www.shaicoggins.com/index.php/forum/

But, I can still access the individual forum posts using their direct links.

I've checked and re-checked the settings. Searched through this forum for answers, etc.

However, I still can't find the solution to this issue. Any ideas what could be the problem and how can I fix it?

Thank you!

I was afraid you'd say that (permalink structure).

I did try removing the index.php, and sure enough, it worked.

It's weird why this has suddenly stopped working though. Before I upgraded, the forum index worked even w/the index.php. So, not sure what would've changed.

On using index.php: My dilemma is from a SEO perspective. The reason I kept the index.php in my URL is because I was told  that changing the permalinks of my blog will result to some kind of search engine penalty. The permalink structure I'm using  has been around for the last 3-4 years. And, I have content that might suffer in terms of search engine traffic to start with.

Not to mention, the backlinks and the nightmare of having to fix several internal links.

So now, I will have to make the decision of whether it's worth risking all the repercussions of changing permalinks, just for Simple:Forum. 

I will investigate. But, if it's not worth it, I might have to scrap the idea of using this forum plugin.

A real shame if I have to, because I am enjoying using this plugin.

In any case, thank you very much for taking the time to have a look & offer your suggestions. Really appreciated!

there is another option to editing SPF

A plugin that I have found useful - Redirection - generates 'Page Moved' http codes quite well and and save SEO and SEM efforts.

All of your content appears to still be alive to both web searhers and folks whom may have you bookmarked.

Search engines will find the 'Page Moved' codes and quietly, without punishing your rankings, will update their search results as it finds them.

Simply place a regular expression (help is available) similar to /index.php/* in the redirect from and  /$1 in the redirect to, and everything should be fine.

The plugin will also automatically generate redirects for pages and posts which you may move or re-date afterwards, and also maintains full logs and control over 404 errors to see if things are somehow misplaced.