delete an item from a NSMutableArray for a specific key

I am trying to figure out how to delete one item from this NSMutableArray that I am using for a sectioned table. This is how I build the data source:

listOfItems = [[NSMutableArray alloc] init];

NSArray *appleComputers = [NSArray arrayWithObjects:@"iPhone",@"iPod",@"MacBook",@"MacBook Pro",nil];
NSDictionary *appleComputersDict = [NSDictionary dictionaryWithObject:appleComputers forKey:@"Computers"];

NSArray *otherComputers = [NSArray arrayWithObjects:@"HP", @"Dell", @"Windows", nil];
NSDictionary *otherComputersDict = [NSDictionary dictionaryWithObject:otherComputers forKey:@"Computers"];

[listOfItems addObject:appleComputersDict];
[listOfItems addObject:otherComputersDict];

I am trying to figure out how to delete, say "iPod" from this array? I have tried many things, among them the one below, but nothing worked.

    [listOfItems removeObjectAtIndex:indexPath.row];

(problem here is that there is no reference for the actual section...)

Thanks!

UPDATE: This is where I delete the row:

- (void)tableView:(UITableView *)aTableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {

if (editingStyle == UITableViewCellEditingStyleDelete) {


    NSMutableArray * section = [listOfItems objectAtIndex:indexPath.section];    
    [section removeObjectAtIndex:indexPath.row];
[tblSimpleTable reloadData];

} else if (editingStyle == UITableViewCellEditingStyleInsert) {

   // some code...
}

}

Not sure why you're using a dictionary... doesn't seem like you need one. How about just an array of arrays?

listOfItems = [[NSMutableArray alloc] init];

NSMutableArray * appleComputers = [NSMutableArray arrayWithObjects:@"iPhone",@"iPod",@"MacBook",@"MacBook Pro",nil];
[listOfItems addObject:appleComputers];

NSMutableArray * otherComputers = [NSMutableArray arrayWithObjects:@"HP", @"Dell", @"Windows", nil];
[listOfItems addObject:otherComputers];

then

NSMutableArray * section = [listOfItems objectAtIndex:indexPath.section];    
[section removeObjectAtIndex:indexPath.row];

Even if you do need to use the dictionaries, it's still not a big deal... just use NSMutableArray instead of NSArray for your appleComputers or otherComputers and do this:

NSDictionary * section = [listOfItems objectAtIndex:indexPath.section];
NSMutableArray * sectionComputers = [section objectForKey:@"Computers"];    
[sectionComputers removeObjectAtIndex:indexPath.row];

For your example, you'd remove all 'iPod' entries like this (note changes to mutable collections):

listOfItems = [[NSMutableArray alloc] init];

NSMutableArray *appleComputers = [NSMutableArray arrayWithObjects:@"iPhone",@"iPod",@"MacBook",@"MacBook Pro",nil];
NSMutableDictionary *appleComputersDict = [NSMutableDictionary dictionaryWithObject:appleComputers forKey:@"Computers"];

NSMutableArray *otherComputers = [NSMutableArray arrayWithObjects:@"HP", @"Dell", @"Windows", nil];
NSMutableDictionary *otherComputersDict = [NSMutableDictionary dictionaryWithObject:otherComputers forKey:@"Computers"];

[listOfItems addObject:appleComputersDict];
[listOfItems addObject:otherComputersDict];

...

for (NSMutableDictionary *dict in listOfItems) {
    [dict objectForKey:@"Computers" removeObject:@"iPod"];
}

Have you tried [array removeObject:@"iPod"]?