well, problem solved!!!!

i decided to put a 1/8 cog on rather than a 3 3/32 chain (the k710sl is just too sweet!) and man oh man is my drivetrain smoooooooooth!!
(though i was disappointed R&A cycles would not exchange my chain, they just wanted to charge me $25 for a z410! Dixon's gave me the cog for $10!)

the switch definitly made a change for the better!

lessons I learned:
1) a 3/32 cog will NOT work with a 1/8 chain. do not even try

2) rear cogs are very very difficult to get off! (i had to put it in a vise and turn the wheel, and even then it was tough)

thanks for all your help!