performSelectorOnMainThread problem

FROM : Nick Rogers
DATE : Thu Mar 13 02:27:38 2008

Hi,
In my secondary thread I'm doing:
[self performSelectorOnMainThread:@selector(updateProgress) 
withObject:data waitUntilDone:YES];

with the error that self does not recognize the selector updateProgress.
I have imported the main AppController.h into this secondary class 
file. still the problem.

Regards,
Nick