Problem with UITableView as subview in a NIB

[shadowmatter]

The executive summary: I'm trying to use a UITableView as a subview of my window's "main" view; it appears, but when I scroll the window I get the following error message:

2010-11-20 17:17:51.958 xwtf[6997:207] -[NSCFString tableView:cellForRowAtIndexPath:]: unrecognized selector sent to instance 0x5f46550

I have a subclass of ViewController with corresponding NIB file that is loaded by my application delegate. It's your typical New Project template. In that NIB file, I add a UITableView as a subview of view. In Interface Builder, I size it to take up the entire window (i.e. it completely overlaps its parent view).

Now I need to specify a data source and delegate. I create a class named DumbTableHelper like so:

@interface DumbTableHelper : NSObject<UITableViewDelegate, UITableViewDataSource> {
}

So, it's not a subclass of UIViewController, but I'm trying to keep this simple -- all I need is a delegate and data source it can call out to, right? Aside from dealloc, my methods in its .m file are:

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
  return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return 10;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"DumbTableCell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }
    return cell;
}

As you can see, I'm not even configuring any cell; I just specify 10 rows, which is enough to force scrolling. Anyway, in Interface Builder I drag an object from the library into my NIB. I then change its class name to DumbTableHelper and specify it as the data source and delegate of the TableView already there. When I run it, the table appears. When I try to scroll down in the table, I get:

010-11-20 18:19:54.673 xwtf[6997:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCFString tableView:cellForRowAtIndexPath:]: unrecognized selector sent to instance 0x5f46550'
*** Call stack at first throw:
(
	0   CoreFoundation                      0x0259eb99 __exceptionPreprocess + 185
	1   libobjc.A.dylib                     0x0239340e objc_exception_throw + 47
	2   CoreFoundation                      0x025a06ab -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
	3   CoreFoundation                      0x025102b6 ___forwarding___ + 966
	4   CoreFoundation                      0x0250fe72 _CF_forwarding_prep_0 + 50
	5   UIKit                               0x00321d6f -[UITableView(UITableViewInternal) _createPreparedCellForGlobalRow:withIndexPath:] + 619
	6   UIKit                               0x00317e02 -[UITableView(UITableViewInternal) _createPreparedCellForGlobalRow:] + 75
	7   UIKit                               0x0032c69f -[UITableView(_UITableViewPrivate) _updateVisibleCellsNow:] + 1348
	8   UIKit                               0x003247ec -[UITableView layoutSubviews] + 242
	9   QuartzCore                          0x0455c481 -[CALayer layoutSublayers] + 177
	10  QuartzCore                          0x0455c1b1 CALayerLayoutIfNeeded + 220
	11  QuartzCore                          0x045552e0 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 302
	12  QuartzCore                          0x04555040 _ZN2CA11Transaction6commitEv + 292
	13  QuartzCore                          0x04585ebb _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 99
	14  CoreFoundation                      0x0257ff4b __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 27
	15  CoreFoundation                      0x02514b27 __CFRunLoopDoObservers + 295
	16  CoreFoundation                      0x024ddce7 __CFRunLoopRun + 1575
	17  CoreFoundation                      0x024dd350 CFRunLoopRunSpecific + 208
	18  CoreFoundation                      0x024dd271 CFRunLoopRunInMode + 97
	19  GraphicsServices                    0x02d5d00c GSEventRunModal + 217
	20  GraphicsServices                    0x02d5d0d1 GSEventRun + 115
	21  UIKit                               0x002beaf2 UIApplicationMain + 1160
	22  xwtf                                0x00001af4 main + 102
	23  xwtf                                0x00001a85 start + 53
)

So it's calling tableView:cellForRowAtIndexPath: on a.. String? Anyone have any ideas?

I'm sorry if this turns out to be a stupid question -- so far all my UITableViews have been created programmatically by UITableViewController instances, but now I need to add a UITableView as a subview. I've read the Apple guide on table views and Beginning iPhone Development to make sure I'm not missing anything, but to no avail

Thanks!