Okay I am trying to compile a mex file on 64 bit linux, ubuntu to be precise with Matlab 2013a.
First it gave a error that it could not find GLIBCXX_3.4.15
I had the same problem and this worked for me
Navigate to the following path cd /usr/local/MATLAB/R2013a/sys/os/glnxa64/, (your path might varies) then remove the libstdc library (or safer rename it)
sudo mv libstdc++.so.6 libstdc++.so.6.old
I have the same configuration, Ubuntu Linux 64 bit with Matlab 2013a