I just had the same problem.
The solution presented here did not solve the problem for me. After suspend the webcam would not work anymore.
I had the latest version of code for the r5u870 available at http://code.google.com/p/r5u870/.
It ends up that the problem went away when I used code / instructions available at https://bitbucket.org/ahixon/r5u87x. For that i rmmod the r5u870 module and followed the instructions:
sudo apt-get install libglib2.0-dev libusb-dev build-essential gcc automake mercurial
hg clone http://bitbucket.org/ahixon/r5u87x/
sudo make install
sudo r5u87x-loader --reload