I claim absolutely no credit for this, and I apologise if this is a duplicate of instructions contained within other posts on this forum, but hopefully this will save someone from despair at some point. Instructions are on a blog post here - Captcha
This blog looks pretty decent, worth a lunchtime read 
Ahh, nice … larry finger to the rescue again … dude deserves a Linux Wireless Knighthood
We need to get this info to donwatson … I think his onboard card was one of those … and that’s certainly his symptoms.
IIRC, we tried the driver config settings but we didn’t try compiling the driver from larry finger
[EDIT]
The instructions for compiling the Larry Finger (lwfinger) driver on that link are no longer valid … he’s moved all the realtek drivers to a central git repo.
they’d now need to read
sudo apt-get install linux-headers-generic build-essential git
mkdir rtlwifi-lwfinger
cd rtlwifi-lwfinger
git clone http://github.com/lwfinger/rtlwifi_new
cd rtlwifi_new
make
sudo make install
which builds and installs the drivers for
rtl8192ce, rtl8192se, rtl8192de, rtl8188ee, rtl8192ee, rtl8723ae, rtl8723be, and rtl8821ae
all in one go