gcc 3.4.2 warnings

[Rob Burns]

I've been using gcc 3.4.2 lately. It produces a lot of warnings that 
older gcc's didn't. Often I do something like this:

[[MyArray objectAtIndex: i] objectForKey: @"foo"]

in which "foo" is a key in a dictionary. Currently I get hundreds of 
lines of warnings, similar too:

StackModel.m:643: warning: multiple methods named `-objectForKey:' 
found
/System/Library/Headers/Foundation/NSDictionary.h:72: warning: using 
`-(id)objectForKey:(id)aKey'
/System/Library/Headers/Foundation/NSUserDefaults.h:245: warning: also 
found `-(id)objectForKey:(NSString *)defaultName'

Is there any way to turn those warnings off?

Thanks
Rob