Mutex Handle leak with DAQmx

Hi,

I'm using CVI 2015 and DAQmx 15.1.1.

When I use DAQmx functions from user DLL that created by CVI,

there is Mutex handle leak even if after unload that.

For example, WinDbg reports handle leaks on name start with

"National Instruments LabWindows/CVI Data Acquisition MX Library".

Do I need to call some function to clean up this resource?

This is some of debugger trace:

Handle = 0x00000594 - OPEN
Thread ID = 0x00000704, Process ID = 0x0000251c

0xc30cd83a: +0xc30cd83a
0xc2d5b193: +0xc2d5b193
0x43fa6374: +0x43fa6374
0x6a46bf87: +0x6a46bf87
0x6a466ea5: +0x6a466ea5
0x6a451cf7: +0x6a451cf7
0x6a47bfa1: +0x6a47bfa1
0x6a46cbb0: +0x6a46cbb0
0x43f91791: +0x43f91791
0x43fc7b28: +0x43fc7b28
0x43f78d6e: +0x43f78d6e
0x77ebe7ac: ntdll!NtCreateMutant+0x0000000c
0x74a8b7bb: KERNELBASE!CreateMutexExW+0x000000cb
0x74ab1c95: KERNELBASE!CreateMutexA+0x00000075
0x02af2188: <Unloaded_DllProject.dll>+0x00002188
--------------------------------------
Handle = 0x000005d8 - OPEN
Thread ID = 0x00000704, Process ID = 0x0000251c

0xc30cd83a: +0xc30cd83a
0xc2d5b193: +0xc2d5b193
0x43fa6374: +0x43fa6374
0x6a46bf87: +0x6a46bf87
0x6a466ea5: +0x6a466ea5
0x6a451cf7: +0x6a451cf7
0x6a47bfa1: +0x6a47bfa1
0x6a46cbb0: +0x6a46cbb0
0x43f91791: +0x43f91791
0x43fc7b28: +0x43fc7b28
0x43f78d6e: +0x43f78d6e
0x77ebe7ac: ntdll!NtCreateMutant+0x0000000c
0x74a8b7bb: KERNELBASE!CreateMutexExW+0x000000cb
0x74ab1c95: KERNELBASE!CreateMutexA+0x00000075
0x02af2188: <Unloaded_DllProject.dll>+0x00002188
--------------------------------------
Displayed 0x66 stack traces for outstanding handles opened since the previous snapshot.
0:011> !handle 5d8 f
Handle 5d8
  Type         	Mutant
  Attributes   	0
  GrantedAccess	0x1f0001:
         Delete,ReadControl,WriteDac,WriteOwner,Synch
         QueryState
  HandleCount  	102
  PointerCount 	3342236
  Name         	\Sessions\1\BaseNamedObjects\National Instruments LabWindows/CVI Data Acquisition MX Library 9500
  Object Specific Information
    Mutex is Free