Originally posted by Ed Holland
Hi again,
P.S. Just rushed out to check the wear on my 2 year old chain (about 7000 miles on it). To my horror it is about 1/4" longer than the supposed 12" And Sheldon says to replace if it is 1/8" over. Oh the shame of it 
Another trip to the bike shop this weekend.
Ed
Double check the wear on your cogs and chainrings. There is a possibility the gears have 'mated' with your worn chain, so if you buy a new chain, excessive wear in the drivetrain will result due to the misaligment between worn gears and a new chain.
-- R. Chan