3110cn laserjet - Additional memory not recognized

I have recently purchased a 3110cn laserjet printer, along with a multi-protocol card for wireless printing and a 512MB memory module. The card was very easy to install and works perfectly, but the printer does not seem to recognize the memory module (both my computer and the printer's "Printer Settings" sheet only show 128MB of memory). I have removed and reinstalled the card several times, and the printer has failed to recognize the module each time. Is this the result of bad memory, or something else?

Thanks.