For some but not all of the visitors to my blog, when they hit "submit comment" they simply get a white page and the comment doesn't make it either to the moderation queue or to the site. In fact, it happens to me too! It's not a plug-in issue, as it happens whether or not there are any plug-ins plugged in. And it's not a wordpress version issue, as this happened before I upgraded to WP 2.6.1 (in fact, I thought the upgrade would make a difference, but it didn't). And it doesn't seem to be a theme issue. Any other suggestions?