Here is a couple of minor clean up Kirill has suggested:
1) On C++ side I still have concerns. Statics is inconsistent with other members of D3DPipelineManager. Why all other members are not statics ?
  Other way to not waste memory is: do not hold message and generate it on request (holding temporary buffer on the stack).

2) Also I`d like to see
    static char messageBuffer[MAX_WARNING_MESSAGE_LEN];
    static char* warningMessage = NULL;
as a members of D3DPipelineManager and messageBuffer memory allocated dynamically if needed.