MFMailComposeViewController not presenting with attachment

[architectpianist]

Hi,
I'm trying to attach a CSV file to an email.
The code I have is below:

if ([mailClass canSendMail]) 
	{
		MFMailComposeViewController *email = [[MFMailComposeViewController alloc] init];
		email.mailComposeDelegate = self;
			
		[email setSubject:subject];
		[email setMessageBody:body isHTML:isHTML];
		if (attachment) 
		{
			if ([attachment isKindOfClass:[NSString class]])
			{
				NSString *csvFile = (NSString *)attachment;
				NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
				NSString *thePath = [NSString stringWithFormat:@"%@/valuetable.csv", [paths objectAtIndex:0]];
				[csvFile writeToFile:thePath atomically:NO encoding:NSStringEncodingConversionAllowLossy error:NULL];
				NSData *attachmentData = [NSData dataWithContentsOfFile:thePath];
				[email addAttachmentData:attachmentData mimeType:@"text/csv" fileName:@"Values"];
				[[NSFileManager defaultManager] removeItemAtPath:thePath error:NULL];					
			}
		}
		[email setModalPresentationStyle:UIModalPresentationPageSheet];	
		[email.navigationBar setBarStyle:UIBarStyleBlackOpaque];
		[self changeKeyboardToNormal:nil];
		[self presentModalViewController:email animated:YES];
		[email release];
	}

The adding attachment code is definitely being called, and the attachmentData object is initialized properly. When I attach an NSData object containing a UIImage, it works. But when using a CSV file, the modal view controller doesn't present itself. Any explanations?
Thanks for any suggestions!

EDIT: Sorry, careless mistake! I was presenting the modal view controller from another modal view controller.