Unpredictable EXC_BAD_ACCESS on FMOD OpenCallback - c++

Question

I'm getting a strange crash, manifesting itself as an EXC_BAD_ACCESS that always happens somewhere on the call stack of a thread opened by FMOD calling it's OpenCallback (the function that is called when FMOD can't find a sound in memory so needs to load it from the disk). The crash comes at a number of different places and I can't seem to find any reason why this changes, since the execution path is essentially the same. One thing I've noticed though is that there are two calls to the same non-recursive constructor adjacent to each other in the call stack. That is, the debugger (Xcode/LLDB, but I've tried it with Xcode/GDB) thinks that this constructor is calling itself, but it isn't.
Another thing I noticed is that the offsets for these calls are different, even though they're referring to the same function. Does anyone know what might be going on? I'm pretty stuck since I don't even know what this kind of problem is called (and therefore can't Google it).
Here's a call stack for one of the crashes (some things are renamed for anonymity, but I tried to keep the naming convention consistent). Notice that the CString and PIFilePath constructors are called twice each, adjacently.
* thread #49: tid = 0x6003, 0x009d3220 MyProject`SpinLock::Lock() + 64 at spinlock.h:73, stop reason = EXC_BAD_ACCESS (code=2, address=0xb01f7ffc)
frame #0: 0x009d3220 MyProject`SpinLock::Lock() + 64 at spinlock.h:73
frame #1: 0x0099d8e0 MyProject`tcmalloc::CentralFreeList::RemoveRange(void**, void**, int) + 160 at central_freelist.cc:211
frame #2: 0x009b4989 MyProject`tcmalloc::ThreadCache::FetchFromCentralCache(unsigned long, unsigned long) + 281 at thread_cache.cc:149
frame #3: 0x009d66fc MyProject`tcmalloc::ThreadCache::Allocate(unsigned long, unsigned long) + 332 at thread_cache.h:330
frame #4: 0x009ce123 MyProject`do_malloc + 227 at tcmalloc.cc:960
frame #5: 0x009ce1e5 MyProject`do_malloc_or_cpp_alloc + 85 at tcmalloc.cc:897
frame #6: 0x009d1285 MyProject`MallocBlock::Allocate(unsigned long, int) + 517 at debugallocation.cc:534
frame #7: 0x009ce460 MyProject`DebugAllocate + 48 at debugallocation.cc:968
frame #8: 0x011cc942 MyProject`malloc + 50
frame #9: 0x00a80bbf MyProject`CSystemUtilities::CSAllocate(long, unsigned long, void*) + 47 at CSystemUtilities.cpp:2358
frame #10: 0x96a08d17 CoreFoundation`CFAllocatorAllocate + 343
frame #11: 0x96a0de4b CoreFoundation`__CFStringChangeSizeMultiple + 1179
frame #12: 0x96a219d6 CoreFoundation`CFStringCreateMutableCopy + 454
frame #13: 0x00a9bae2 MyProject`CString::SetCFString(__CFString const*, bool) + 114 at CString.cpp:527
frame #14: 0x00a9bcb0 MyProject`CString::CString(CString const&) + 112 at CString.cpp:189
frame #15: 0x00a9bc1f MyProject`CString::CString(CString const&) + 47 at CString.cpp:190
frame #16: 0x00aa3a9e MyProject`PIFilePath::NormalisePath(CString const&, long, bool, unsigned short) + 2142 at PIFilePath.cpp:2021
frame #17: 0x00aa2dc9 MyProject`PIFilePath::FindPathInList(CString const&, std::vector<CString, std::allocator<CString> > const&) + 89 at PIFilePath.cpp:1716
frame #18: 0x00aa3d26 MyProject`PIFilePath::IsAbsolutePath(CString const&) + 134 at PIFilePath.cpp:465
frame #19: 0x00aa62d1 MyProject`PIFilePath::ApplyMappingsToPath(CString const&, CString const&, bool) + 1041 at PIFilePath.cpp:1323
frame #20: 0x00aa292d MyProject`PIFilePath::TranslatePath(CString const&) const + 4157 at PIFilePath.cpp:1645
frame #21: 0x00aa15ad MyProject`PIFilePath::SetPath(CString const&, PIFilePath::ConvertPathMode) + 253 at PIFilePath.cpp:175
frame #22: 0x00aa1460 MyProject`PIFilePath::PIFilePath(CString const&, PIFilePath::ConvertPathMode) + 96 at PIFilePath.cpp:122
frame #23: 0x00aa13dd MyProject`PIFilePath::PIFilePath(CString const&, PIFilePath::ConvertPathMode) + 61 at PIFilePath.cpp:123
frame #24: 0x00becad8 MyProject`FileAttributes + 88 at pi_files.cpp:3341
frame #25: 0x0090702b MyProject`SystemStuff::CWinFS::Exists(char const*) + 219 at fsWin.cpp:627
frame #26: 0x008e2892 MyProject`SystemStuff::CMultiFS::FindFS(char const*) + 162 at fsMulti.cpp:390
frame #27: 0x008e1466 MyProject`SystemStuff::CMultiFS::Open(SystemStuff::RCPtr<SystemStuff::IBlock>&, char const*, unsigned long) + 134 at fsMulti.cpp:223
frame #28: 0x008db911 MyProject`SystemStuff::CDispatchFS::Open(SystemStuff::RCPtr<SystemStuff::IBlock>&, char const*, unsigned long) + 321 at fsDispatch.cpp:158
frame #29: 0x008cbb89 MyProject`SystemStuff::FS::Open(SystemStuff::RCPtr<SystemStuff::IBlock>&, char const*, unsigned long) + 233 at fs.cpp:135
frame #30: 0x00985611 MyProject`OpenCallback(char const*, int, unsigned int*, void**, void**) + 177 at sndFMODEx.cpp:324
frame #31: 0x029ecf59 libfmodex.dylib`FMOD::DSP::disconnectFrom(FMOD::DSP*) + 25999
frame #32: 0x029ee7cb libfmodex.dylib`FMOD_File_SetDiskBusy + 4861
frame #33: 0x02a0c15b libfmodex.dylib`FMOD::SystemI::createSoundInternal(char const*, unsigned int, unsigned int, unsigned int, FMOD_CREATESOUNDEXINFO*, FMOD::File**, bool, FMOD::SoundI**) + 2413
frame #34: 0x0298b6aa libfmodex.dylib
frame #35: 0x02a11d2c libfmodex.dylib`FMOD::SystemI::createSoundInternal(char const*, unsigned int, unsigned int, unsigned int, FMOD_CREATESOUNDEXINFO*, FMOD::File**, bool, FMOD::SoundI**) + 25918
frame #36: 0x91b6d557 libsystem_c.dylib`_pthread_start + 344
This is the crash I get about 40% of the time, and the other 60% of the time it fails at NormalisePath (but the callstack above that is the same).