Yesterday I noticed for the first time that commenting went down. After trying to comment (logged in as administrator), I was taken to a blank wp-comments-post.php page. There was no apparent reason for this; I hadn't been in to any pages, messing with any code, that affected commenting.
I first started trying to debug this by turning off all plugins; no luck. I then upgraded to 2.8.1; no luck. I've searched the support forums looking for other people's similar problems and tried their suggestions; no luck. There seems to be quite a few people that have had this problem, but no clear solution. (if there is, someone needs to make a sticky post for this)
The one thing that did work is that I switched to the Default theme, and comments were working again. So there's something wrong with the theme that I'm using/modifying, but I don't know where to begin looking for the mistake that is there.
I would greatly appreciate someone's help on this matter. My website is http://tinyurl.com/mod6gw and I'll be monitoring this topic, if someone needs me to post further information.