crash from cg call when called from multiple threads - GeForce GTX 750 TI

I am working on an image display application in which I am using cg shaders from multiple threads. It is a Windows application and each thread has its own HGLRC. But at times the cg calls like cgGLIsProfileSupported gets crashed when simultaneously accessed from different threads. The call stack of the crash is as from WinDbg is as below. For both thread the crash point and call stack is similar

: KERNELBASE!UnhandledExceptionFilter+0x157
: ntdll!RtlUserThreadStart$filt$0+0x38
: ntdll!_C_specific_handler+0x96
: ntdll!RtlpExecuteHandlerForException+0xd
: ntdll!RtlDispatchException+0x373
: ntdll!KiUserExceptionDispatch+0x3a
: cg!cgiSetProfileOptions+0x835
: cg!cgiGetProfile+0x10cd
: cg!cgiAcquireWriteLock+0x2a
: cgGL!cgGLIsProfileSupported+0x12

It is observed that the issue occurs only for GeForce GTX 750 TI card. The issue is not observed for other cards like GTX 1050 or lower cards like GTX 640. Have anybody observed similar issues and any suggestions/solutions for the problem?

The Cg Toolkit is a legacy NVIDIA toolkit no longer under active development or support.

I think nVidia will not fix this problem.