Weird WebThread Crash in iOS

I'm getting a strange crash in the webthread, happening when releasing a URLResponse. I did not directly manipulate the contents of the URLCache, so what could be the cause of this problem?

Here's the crash log for reference:

Incident Identifier: E4116BAA-7467-42F8-B28E-7A1FA2D12278
CrashReporter Key:   dcaac993b4bfa7e5015f07b0ffc611182b196e57
Hardware Model:      iPad2,1
Process:         *** [6299]
Path:            /var/mobile/Applications/
Identifier:      ***
Version:         ??? (???)
Code Type:       ARM (Native)
Parent Process:  launchd [1]

Date/Time:       2012-06-25 11:11:59.347 +0800
OS Version:      iPhone OS 5.0.1 (9A405)
Report Version:  104

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x42810008
Crashed Thread:  2

Thread 0 name:  Dispatch queue: com.apple.main-thread
Thread 0:
0   libsystem_kernel.dylib          0x30367010 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x30367206 mach_msg + 50
2   CoreFoundation                  0x37cea41c __CFRunLoopServiceMachPort + 120
3   CoreFoundation                  0x37ce911a __CFRunLoopRun + 818
4   CoreFoundation                  0x37c6c4d6 CFRunLoopRunSpecific + 294
5   CoreFoundation                  0x37c6c39e CFRunLoopRunInMode + 98
6   GraphicsServices                0x37a43fc6 GSEventRunModal + 150
7   UIKit                           0x317ec73c UIApplicationMain + 1084
8   ***                             0x00002d80 0x1000 + 7552
9   ***                             0x00002c9c 0x1000 + 7324

Thread 1 name:  Dispatch queue: com.apple.libdispatch-manager
Thread 1:
0   libsystem_kernel.dylib          0x303673b4 kevent + 24
1   libdispatch.dylib               0x308d2f74 _dispatch_mgr_invoke + 708
2   libdispatch.dylib               0x308d2c92 _dispatch_mgr_thread + 30

Thread 2 name:  WebThread
Thread 2 Crashed:
0   libobjc.A.dylib                 0x3785cfbc objc_msgSend + 16
1   CoreFoundation                  0x37c5f470 CFRelease + 88
2   CFNetwork                       0x33adc9e4 URLResponse::~URLResponse() + 72
3   CoreFoundation                  0x37c5f524 CFRelease + 268
4   CFNetwork                       0x33b2e278 __CFCachedURLResponse::~__CFCachedURLResponse() + 60
5   CFNetwork                       0x33b2e07c _ZL30_CFCachedURLResponseDeallocatePKv + 12
6   CoreFoundation                  0x37c5f524 CFRelease + 268
7   CFNetwork                       0x33b2e39a __CFURLCacheNode::~__CFURLCacheNode() + 30
8   CFNetwork                       0x33b2fba6 __CFURLCache::RemoveResponseFromCacheContainers(__CFURLCacheNode*, _CFCachedURLResponse const*, __CFString const*, bool) + 110
9   CFNetwork                       0x33b2fc92 __CFURLCache::RemoveLRUCachedItems(long, __CFURLCacheNode*) + 150
10  CFNetwork                       0x33b308ac __CFURLCache::CreateAndStoreCacheNode(__CFURLCacheNode*, _CFCachedURLResponse const*, __CFString const*, _CFURLRequest const*, void const*, bool, bool&) + 92
11  CFNetwork                       0x33b30aa4 AddCacheTask(__CFURLCacheNode*) + 280
12  CFNetwork                       0x33b32778 CFURLCacheAddCachedResponseForRequest + 136
13  CFNetwork                       0x33ade7b2 URLConnectionClient::_clientWillCacheResponse(URLConnectionClient::ClientConnectionEventQueue*) + 478
14  CFNetwork                       0x33ad353e URLConnectionClient::ClientConnectionEventQueue::processAllEventsAndConsumePayload(XConnectionEventInfo<XClientEvent, XClientEventParams>*, long) + 418
15  CFNetwork                       0x33ad323c URLConnectionClient::processEvents() + 100
16  CFNetwork                       0x33ad3172 MultiplexerSource::perform() + 150
17  CoreFoundation                  0x37ceaafc __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 8
18  CoreFoundation                  0x37cea2c8 __CFRunLoopDoSources0 + 208
19  CoreFoundation                  0x37ce906e __CFRunLoopRun + 646
20  CoreFoundation                  0x37c6c4d6 CFRunLoopRunSpecific + 294
21  CoreFoundation                  0x37c6c39e CFRunLoopRunInMode + 98
22  WebCore                         0x32743128 _ZL12RunWebThreadPv + 396
23  libsystem_c.dylib               0x377dac16 _pthread_start + 314
24  libsystem_c.dylib               0x377daad0 thread_start + 0

Thread 3 name:  com.apple.NSURLConnectionLoader
Thread 3:
0   libsystem_kernel.dylib          0x30367010 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x30367206 mach_msg + 50
2   CoreFoundation                  0x37cea41c __CFRunLoopServiceMachPort + 120
3   CoreFoundation                  0x37ce9154 __CFRunLoopRun + 876
4   CoreFoundation                  0x37c6c4d6 CFRunLoopRunSpecific + 294
5   CoreFoundation                  0x37c6c39e CFRunLoopRunInMode + 98
6   Foundation                      0x34fbbbc2 +[NSURLConnection(Loader) _resourceLoadLoop:] + 302
7   Foundation                      0x34fbba8a -[NSThread main] + 66
8   Foundation                      0x3504f59a __NSThread__main__ + 1042
9   libsystem_c.dylib               0x377dac16 _pthread_start + 314
10  libsystem_c.dylib               0x377daad0 thread_start + 0

Thread 4 name:  com.apple.CFSocket.private
Thread 4:
0   libsystem_kernel.dylib          0x30377570 __select + 20
1   CoreFoundation                  0x37cee66a __CFSocketManager + 726
2   libsystem_c.dylib               0x377dac16 _pthread_start + 314
3   libsystem_c.dylib               0x377daad0 thread_start + 0

Thread 5 name:  WebCore: CFNetwork Loader
Thread 5:
0   libsystem_kernel.dylib          0x30367010 mach_msg_trap + 20
1   libsystem_kernel.dylib          0x30367206 mach_msg + 50
2   CoreFoundation                  0x37cea41c __CFRunLoopServiceMachPort + 120
3   CoreFoundation                  0x37ce9154 __CFRunLoopRun + 876
4   CoreFoundation                  0x37c6c4d6 CFRunLoopRunSpecific + 294
5   CoreFoundation                  0x37c6c39e CFRunLoopRunInMode + 98
6   WebCore                         0x3276c69e _ZN7WebCoreL15runLoaderThreadEPv + 122
7   libsystem_c.dylib               0x377dac16 _pthread_start + 314
8   libsystem_c.dylib               0x377daad0 thread_start + 0

Thread 6:
0   libsystem_kernel.dylib          0x30377cd4 __workq_kernreturn + 8
1   libsystem_c.dylib               0x377d530a _pthread_wqthread + 610
2   libsystem_c.dylib               0x377d509c start_wqthread + 0

Thread 2 crashed with ARM Thread State:
    r0: 0x0ae93de0    r1: 0x30da109c      r2: 0x00000001      r3: 0x00000000
    r4: 0x42810000    r5: 0x0ae93de4      r6: 0x3f000000      r7: 0x012e7d68
    r8: 0x3f936690    r9: 0x0c368427     r10: 0x0000011c     r11: 0x00000080
    ip: 0x3f910814    sp: 0x012e7d34      lr: 0x37c5f477      pc: 0x3785cfbc
  cpsr: 0x20000030