Inconsistent JSON Parsing in XCODE (Cocoa error 3840)

Inconsistent JSON Parsing in XCODE (Cocoa error 3840)

I download data through two specially written API's using the same class
and method. One of the API's works well but the other one produces an
error 3840.
Here is the code:
+(NSDictionary *)executeSearchRequest:(NSString *)usingThisURL
{
NSError* error = nil;
usingThisURL = [NSString
stringWithFormat:@"%@&format=json&nojsoncallback=1", usingThisURL];
NSLog(@"URL Sent to Athletic.net: %@", usingThisURL);
// usingThisURL = [usingThisURL
stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
// Preceding line makes one call fail and does not correct problem with
other.
NSLog(@"[%@ %@] sent %@", NSStringFromClass([self class]),
NSStringFromSelector(_cmd), usingThisURL);
NSData *jsonData = [[NSString stringWithContentsOfURL:[NSURL
URLWithString:usingThisURL] encoding:NSUTF8StringEncoding error:nil]
dataUsingEncoding:NSUTF8StringEncoding];
NSLog(@"jsonData: [%@]",jsonData);
NSDictionary *results = jsonData ? [NSJSONSerialization
JSONObjectWithData:jsonData
options:NSJSONReadingMutableContainers|NSJSONReadingMutableLeaves
error:&error] : nil;
NSLog(@"json NSDictionary results: [%@]", results);
if (error) NSLog(@"[%@ %@] JSON error: %@", NSStringFromClass([self
class]), NSStringFromSelector(_cmd), error.localizedDescription);
NSLog(@"[%@ %@] received %@", NSStringFromClass([self class]),
NSStringFromSelector(_cmd), results);
return results;
}
The data for the one looks that parses correctly like this when I pull it
down using Terminal and a "curl -v" command:
{"Search":{"Athlete":
[{"@IDAthlete":"0123456","@FirstName":"John","@LastName":"Doe","@Gender":"M","@IDSchool":"148","@SchoolName":"All
American HS","@City":"Union","@State":"ST"},
{"@IDAthlete":"654321`","@FirstName":"Jane","@LastName":"Doe","@Gender":"F","@IDSchool":"18266","@SchoolName":"Any
Ol HS","@City":"Union","@State":"ST"},]}}
The data that does not parse looks like this:
{"ROOT":{"@xmlns:sql":"urn:schemas-microsoft-com:xml-sql"/* School Info
*/,"row":
{"@SelectedAthlete":"235434"},"HasTrack":{"@AthleteID":"235434"},"Athlete":
{"@IDAthlete":"235434","@SchoolID":"148","@FirstName":"Jane","@LastName":"Doe","@Gender":"F",
"SchType":[{"@SortID":"1","@SchoolType":"High
School","@DispSchoolTypeAbbrev":"HS","School":
{"@IDSchool":"148","@RegionID":"1","@SchoolName":"All
American","SchoolDivision":[{"@DivisionID":"21036","Season":{"@IDSeason":"2012","@Display":"2012","Grade":
{"@SingularGradeDesc":"11th
Grade","@IDGrade":"11","Distance":[{"@Distance":"2600.00","@Units":"Meters","Result":
...
The only thing I can figure is that JSON is choking on the description
that begins with xmlns:sql OR that this indicates I have an XML file
rather than JSON format. (I have parsed this data in XML before.)
Can I simply manipulate the data as is or do I need to have the generating
API modified?
Thanks for your help!