Problems with Running examples

[zxwu]

Hi Nitish,
I compiled cudamat on Centos 6.3.When I run the test in cudamat,it seemed that the result of test_pow_matrix function was not very stable.I failed sometimes and succeeded when I tried again.

Besides, after setup the examples,I runned the rbm , it failed and prompted no gpu found,but I can run cuda-convnet.I tried both on K20 and Quardo 4000, is this because of the system?