Can't uninstall Special Menu Items

When I attempt to uninstall Special Menu Items module via the standard method, the module continues to appear in the list of modules.

After removing the checkmark from Special Menu Items in the Modules list, I then load the Uninstall tab, where I check the box for Special Menu Items and confirm deletion.

However, when I return to the Modules list, Special Menu Items still appears there, with the check box unchecked. It no longer appears in the list of items to uninstall; if I want to repeat the process, I must check the box in the Modules list and save configuration, then uncheck the box and save again. Then I am once again able to attempt to uninstall, but no matter how many times I try, the process repeats.