NSTextField value binding (feeling like a newbie)

FROM : Jeff LaMarche
DATE : Tue Mar 18 22:33:14 2008

Working with IB3 to try and get my bearings again, and I know I'm 
doing something stupid here. I have an NSTextField inside an 
NSScrollView created in IB3. I have bound the value binding of the 
NSTextField to an NSString called feedback, exposed as an Objective-C 
2.0 property,declared like this:

@property (retain, nonatomic) NSMutableString *feedback;

In my implementation, use @synthesize to have it build the accessors 
and mutators. The binding is set to Continuously Updates Values, and 
is not editable, and has rich text turned off. If I run my program, 
and make changes to the string (feedback), those are not reflected in 
the text field even though I can tell through the debugger that the 
string is changing.

I suspect I'm doing something really stupid, but I'm stumped, and 
nothing in the archives pointed me in the right direction. The 
Objective-C 2.0 book seems to indicate that properties are KVC 
compliant, but maybe I missed something?

Any thoughts would be much appreciated.

Thanks,
Jeff