CUDAPP 1.1 cudppSort configuration error (Invalid configuration argument) - debugging

Question

I am trying to call cudppSort to sort a set of keys/values. I'm using the following code to set up the sort algorithm:
CUDPPConfiguration config;
config.op = CUDPP_ADD;
config.datatype = CUDPP_UINT;
config.algorithm = CUDPP_SORT_RADIX;
config.options = CUDPP_OPTION_KEY_VALUE_PAIRS | CUDPP_OPTION_FORWARD | CUDPP_OPTION_EXCLUSIVE;
CUDPPHandle planHandle;
CUDPPResult result = cudppPlan(&planHandle, config, number_points, 1, 0);
if (CUDPP_SUCCESS != result) {
printf("ERROR creating CUDPPPlan\n");
exit(-1);
}
The program exits, however on the line:
CUDPPResult result = cudppPlan(&planHandle, config, number_points, 1, 0);
and prints to stdout:
Cuda error: allocScanStorage in file 'c:/the/path/to/release1.1/cudpp/src/app/scan_app.cu' in line 279 : invalid configuration argument.
I looked at the line in scan_app.cu. It is,
CUT_CHECK_ERROR("allocScanStorage");
So apparently my configuration has an error that is causing the allocScanStorage to bomb out. There are only two calls to CUDA_SAFE_CALL in the function and I don't see a reason why either has anything to do with the configuration.
What is wrong with my configuration?

Answer 1

So that this doesn't sit around as an unanswered question (I'm not sure if this is the right SO etiquette but it seems like an answered question shouldn't sit around unanswered...), I'm copying the comment I made above here as an answer since it was the solution:
I figured this out (I'm still learning CUDA at the moment.) Because the error checking is asynchronous errors can show up in strange places if you don't check for them from time to time. My code had caused an error before I called cudppPlan but because I didn't check for errors the cudppPlan reported the error as if it was in cudppPlan.