diff --git a/AFGowallaAPI.m b/AFGowallaAPI.m
index de92864..a115b8b 100644
--- a/AFGowallaAPI.m
+++ b/AFGowallaAPI.m
@@ -82,7 +82,7 @@ static NSOperationQueue *_operationQueue = nil;
 
 + (NSMutableURLRequest *)requestWithMethod:(NSString *)method path:(NSString *)path parameters:(NSDictionary *)parameters {	
 	NSMutableURLRequest *request = [[[NSMutableURLRequest alloc] init] autorelease];
-	NSMutableDictionary *headers = [_defaultHeaders mutableCopy];
+	NSMutableDictionary *headers = [NSMutableDictionary dictionaryWithDictionary:_defaultHeaders];
 	NSURL *url = nil;
 	
 	NSMutableArray *mutableParameterComponents = [NSMutableArray array];
diff --git a/AFHTTPOperation.m b/AFHTTPOperation.m
index 37286bb..47395c5 100644
--- a/AFHTTPOperation.m
+++ b/AFHTTPOperation.m
@@ -89,7 +89,7 @@ NSString * const AFHTTPOperationParsedDataErrorKey = @"com.alamofire.http-operat
         [userInfo setValue:[[self.lastRequest URL] absoluteString] forKey:NSURLErrorFailingURLStringErrorKey];
         [userInfo setValue:data forKey:AFHTTPOperationParsedDataErrorKey];
         
-        error = [[NSError alloc] initWithDomain:NSURLErrorDomain code:[self.lastResponse statusCode] userInfo:userInfo];
+        error = [[[NSError alloc] initWithDomain:NSURLErrorDomain code:[self.lastResponse statusCode] userInfo:userInfo] autorelease];
         
         if (self.callback.errorBlock) {
             self.callback.errorBlock(self.lastRequest, self.lastResponse, error);
diff --git a/AFImageRequestOperation.m b/AFImageRequestOperation.m
index 55772f5..376fc73 100644
--- a/AFImageRequestOperation.m
+++ b/AFImageRequestOperation.m
@@ -33,7 +33,7 @@ static inline CGSize kAFImageRequestRoundedCornerRadii(CGSize imageSize) {
 }
 
 @implementation AFImageRequestOperation
-@synthesize callback;
+@synthesize callback = _callback;
 
 - (id)initWithRequest:(NSURLRequest *)someRequest callback:(AFImageRequestOperationCallback *)someCallback {
 	self = [super initWithRequest:someRequest];
@@ -74,8 +74,8 @@ static inline CGSize kAFImageRequestRoundedCornerRadii(CGSize imageSize) {
 	[super finishWithError:error];
     
     if (error) {
-        if (callback.errorBlock) {
-			callback.errorBlock(error);
+        if (self.callback.errorBlock) {
+			self.callback.errorBlock(error);
 		}
 
         return;