@InqBit: is 137694 khash/s the first shown hash rate? Please run the miner 5 min and than look to the hash rate. The first hash rate is always lower because the first kernel call takes very long.
I see you run the code with without -aggression, please add -aggression=8  or 7 to you parameter to get more performance. -gputhreads is not needed because it is ignored and hard set to 256.

theoretic calculation rate for GTX480: 1401*15/(3733/32+1194/16)=109 MHash/s   (magic numbers are the count of operations from the binary for this implementation)

Mhh in my theoretic calculation  I assumed 109 MHash/s for a GTX480. I think I must check if my operation count for fermi is right.
Can someone with a GTX480 run the code under linux without -gpugrid.