asihttprequest:在iphone上发布问题

我试图建立一个连接我的应用程序和互联网服务,我正在使用AsitpRequest,但我有一个小问题。当我使用WiFi时,一切都很好,但当我关闭WiFi并使用GPRS(EDGE)或3G时,一切似乎都不起作用。我应该换点东西吗。 这是我的一些代码

[self setRequest:[ASIFormDataRequest requestWithURL:[NSURL URLWithString:@"example.url.php"]]];

[request setPostValue:textString forKey:@"mytext"];
[request setData:imageData withFileName:theFinal andContentType:@"image/png" forKey:@"userfile"];
[request setPostValue:textString2 forKey:@"description"];
[request setPostValue:latitude forKey:@"latitude"];
[request setPostValue:longitude forKey:@"longitude"];
[request setPostValue:finalIdString forKey:@"city_id"];

[request setTimeOutSeconds:60];
[request setUploadProgressDelegate:progressIndicator];
[request setDelegate:self];
[request setDidFailSelector:@selector(uploadFailed:)];
[request setDidFinishSelector:@selector(uploadFinished:)];
[request startAsynchronous];