I created a top level category. I then decided to put it as a subcategory of another top level category. After I edited the category and changed the parent category, when I went to save it, I received the following error message and the change was not saved:

Error displaying the error page: Table 'a' was not locked with LOCK TABLES SQL=SELECT a.*, SUM(b.home) AS home,b.language,l.image,l.sef,l.title_native FROM inp_menu_types AS a LEFT JOIN inp_menu AS b ON b.menutype = a.menutype AND b.home != 0 LEFT JOIN inp_languages AS l ON l.lang_code = language WHERE (b.client_id = 0 OR b.client_id IS NULL) GROUP BY a.id, a.menutype, a.description, a.title, b.menutype,b.language,l.image,l.sef,l.title_native: BIGINT UNSIGNED value is out of range in '(`my_test`.`inp_gpstools_categories`.`nleft` * -(1))' SQL=UPDATE inp_gpstools_categories SET nleft = nleft * -1, nright = nright * -1 WHERE nleft >= 4 AND nright <= 5

I was able to get around this by simply deleting the category that I wanted to move. Then I re-created the category and set the new parent category during the category creation process and it worked fine but I wanted you to know about the problem with moving the category.