how to reproduce)
"Create Screen" on Configuration/Screens window
Name: EmptyScreenTest
Columns: 1
Rows: 1
Select "Edit" in "EmptyScreenTest"
Select "Change"
Select just "Save" without set "Graph name"

1. refer to 1st attached image
   You can see "Item added" and "ERROR: No permission!"
2. refer to 2nd attached image
   Additionally, this garbage data(screenitemid=3) is stored into "screens_items" table.
   Quote:
   mysql> select * from screens_items;
   ----------------------------------------------------------------------------------------------------------+

   screenitemid

   screenid

   resourcetype

   resourceid

   width

   height

   x

   y

   colspan

   rowspan

   elements

   valign

   halign

   style

   url

   dynamic

   ----------------------------------------------------------------------------------------------------------+

   2	2	2	2	0	0	0	0	2	0	0	0	0	0		0
   3	3	0	0	500	100	0	0	0	0	0	0	0	0		0

   ----------------------------------------------------------------------------------------------------------+
   2 rows in set (0.00 sec)
   I investigated a little. I think the cause is validation check in "screenedit.php". The $_REQUEST["resourceid"] hasn't checked(it's set zero) when we try to save screen cell. After that, we get error since it cannot find "resourceid".
   We should check whether $_REQUEST["resourceid"] has a value configured from "Resource".

http://www.zabbix.com/forum/showthread.php?p=44940