Issue with permissions

[iggydarsa]

I have a problem with the permission types but let me give you the background before my question:
I created a custom list, and a special type of permission that only the users with that permission can access the list. The rights for this permission type are:

List Rights -> Manage List, Cancel Check-Out, Add Items, Edit Items, View Items

Site Rights -> Browse Directories, View Pages

Personal Rights -> All 4 (Manage, Update, Add/Remove, Create)

In my custom list, the item-level permission is:
Read Access: All Items
Edit Access: Only their own

Now, the problem is, eventhough the edit access is "only their own" the user can edit any item. Am i doing something wrong? Any response will be appreciated.

Thanks