When I attempt to add a new category, it says that the new category already exists, regardless of what I put in it. Is this a common problem that is easy to fix? I apologize if the question has been asked a million times, but it is very frustrating. Thanks!

MMMM, Add a new catigoriy where? You Admin Panel, the DAtabase itself, where?

I actually just found the answer (here it is in case anyone else has the problem and my not know).

Open admin/modules/stories.php and find:
Code:
$check = $db->sql_query("select catid from ".$prefix."_stories_cat where title='$title'");
$catid = intval($catid);

change to:
Code:
$result = $db->sql_query("select catid from ".$prefix."_stories_cat where title='$title'");
$catid = intval($catid);
$check = $db->sql_numrows($result);

also find:
Code:
$check = $db->sql_query("select catid from ".$prefix."_stories_cat where title='$title'");

change to:
Code:
$result = $db->sql_query("select catid from ".$prefix."_stories_cat where title='$title'");
$check = $db->sql_numrows($result);

Those are very good answers. You can also try upgrading your current versions of nuke. Alot of bugs are fixed such as that 1. But Im glad you found your answer because I dont have that problem with version 7.5 nor .6