I had been struggling with this issue for months. Here's what finally worked for me:
Download the latest driver (you might have to install git first)
git clone http://github.com/lwfinger/rtlwifi_new.git
Change into the new directory you just created
cd rtlwifi_new
Compile and install the new driver
make
sudo make install
Edit the settings for the driver
echo "options rtl8723be fwlps=0 swlps=0" | sudo tee /etc/modprobe.d/rtl8723be.conf
It's probably a good idea to take a look at that file to make sure that worked. Some people say the "swlps=0" part of the command above is unnecessary. I'm not sure but it doesn't seem to be hurting anything.
Reboot.
Good luck!