I have a simple Cocoa app using a NSWindowController subclass. In the nib I have set:
if you wrote
TTEst *test3 = (TTEst *)[[NSWindowController alloc] initWithWindowNibName:@"TTEst"];
try instead
TTEst *test3 = [[TTEst alloc] initWithWindowNibName:@"TTEst"];
it makes the difference ! Of course the first line was a mistake...