[pluthb]

I too use a 31 1/4 inch putter and I'm 5'13. For me it is a product of where my arms hang. If you have a face balanced putter, you are much better off cutting off your putter to the right length and it only will cost you about $10. If you don't grip down or invest in a new putter, not necessarily a face balanced putter.
My clubfitter in MN has tested over 3500 people and has found the average length of a putter should be 32 inches. The only reason they sell 34 and 35 inch putters is because they fit in the bag, they don't fit people!