Thanks for your report. There are some questions on how the threading is used in your application. For UIC JPEG encoding, the code is threaded at the sample code level. It looks to me that you are also trying to use other level of threading: ippSetNumThreads() function to set number of processing threads, This function is used to set the internal threading of IPP level functions. If you are using threading at the sample code level, it is suggested disabling the threading at the level function.
Also it looks that you are trying to thread at your application by add some compiler switch /Qparallel. This is also need to be careful that this will not create overthreading with the threading at the sample code level.
How the is linked with IPP libraries, statically, or dynamically? If it is statically link, it needs to call ippInit() function to select correct dispatching code.