check that that we don't load an old version of cuda_ndarray. If so, print a warning.

theano/sandbox/cuda/__init__.py

@@ -80,6 +80,11 @@ if compile_cuda_ndarray:
         from cuda_ndarray.cuda_ndarray import *
 
 if enable_cuda:
+    #check if their is an old cuda_ndarray that was loading instead of the one we compiled!
+    import cuda_ndarray.cuda_ndarray
+    if os.path.join(config.compiledir,'cuda_ndarray','cuda_ndarray.so')!=cuda_ndarray.cuda_ndarray.__file__:
+        print "WARNING: cuda_ndarray was loaded from",cuda_ndarray.cuda_ndarray.__file__,"This is not expected as theano should compile it automatically for you. Do you have a directory called cuda_ndarray in your LD_LIBRARY_PATH environment variable? If so, please remove it as it is outdated!"
+
     from theano.sandbox.cuda.type import CudaNdarrayType
     from theano.sandbox.cuda.var import (CudaNdarrayVariable,
             CudaNdarrayConstant,