Black Sheep,
To be fair to Gulliver, if you follow Diem's first set of instructions, the first document on the A-Z list beginning with R does deal with Rates of PRSI contributions for non-PAYE employees, which is not what Diem intended to refer readers to.
Diem's second set of instructions (and my link) refer to the Rates of Payment which as you've said is a very pertinent issue for retirees in 2012.