NSWorkspace vs NSTask to start iTunes from a sandboxed app

Question

I'm trying to run iTunes from my ObjectiveC app that runs in a sandbox. Apple documentation mentions that 'child processes created with the NSTask class inherit the sandbox of the parent app'. The result is that when running iTunes, some permission error pops up and iTunes is closed. When running it using NSWorkspace methods it does not crash and seems it's running outside any sandbox. Does that mean that i have permission to insert some dynamic library at launch time using DYLD_INSERT_LIBRARIES ? Here's some code:

NSString* appPath = @"/Applications/iTunes.app";
// Get application URL
NSBundle *targetBundle = [NSBundle bundleWithPath:appPath];
NSURL *applicationURL = [targetBundle executableURL];

NSString* libPath = [NSHomeDirectory() stringByAppendingPathComponent:@"myLib.dylib"];
// Environment setup
NSDictionary *config = nil;
NSDictionary *env = [NSDictionary dictionaryWithObject:libPath forKey:@"DYLD_INSERT_LIBRARIES"];

NSNumber *arch = [NSNumber numberWithInt:(int)NSBundleExecutableArchitectureI386];
config = [[NSDictionary alloc] initWithObjectsAndKeys:env, NSWorkspaceLaunchConfigurationEnvironment, 
                                                      arch, NSWorkspaceLaunchConfigurationArchitecture, nil];

// Launch application
[[NSWorkspace sharedWorkspace] launchApplicationAtURL:applicationURL
                          options:0 
                    configuration:config 
                            error:nil];

[config release];

When the above code runs in a sandbox iTunes starts without any lib. Any suggestion?

Thanks, Vlad.