IXACTEngine::GetGlobalVariable crushed application

I have code:

// ...
IXACTEngine* m_pXACTEngine
// ... create m_pXACEngine and so on
XACT_RUNTIME_PARAMETERS xactParams;
ZeroMemory(&xactParams, sizeof(xactParams));
/*
fill xactParams exclude
XACT_RUNTIME_PARAMETERS ::globalSettingsBufferSize; // == 0
XACT_RUNTIME_PARAMETERS ::globalSettingsFlags; // == 0
XACT_RUNTIME_PARAMETERS ::globalSettingsAllocAttributes; // == 0
*/
hr = m_pXACTEngine->Initialize(&xactParams);
if (SUCCEEDED(hr))
{
XACTVARIABLEINDEX xactSpeedOfSoundID =
m_pXACTEngine->GetGlobalVariableInde("SpeedOfSound");
// now xactSpeedOfSoundID == XACTVARIABLEINDEX_INVALID
XACTVARIABLEVALUE nSpeedOfSound = 0;
hr = m_pXACTEngine->GetGlobalVariable(xactSpeedOfSoundID, &nSpeedOfSound);
//...

but m_pXACTEngine->GetGlobalVariable crushed with access violation

call stack:

xactengine2_1.dll!0367ad78()
xactengine2_1.dll!0367bd91()
SoundManager.dll!CSoundManager::create(unsigned long dwLookAheadTime=4294967295, const char * pszGlobalSettings=0x0012fd18, unsigned int nDevId=4672226) Line 604 + 0x23 C++
...

Error report: Unhandled exception at 0x0367ad78 in <some application>: 0xC0000005: Access violation reading location 0x00000000.

>You cannot set/query variables
That is right... But I consider that GetGlobalVariable must return error code rather than crash...