Why hasn't Team Lotus been able to catch mid-pack teams?

This season, Team Lotus (formerly Lotus Racing) got Red Bull transmissions, and Renault engines. They seemed poised to start getting points, but why hasnt it happened yet? I think that Gascoyne's design, though not Newey good, is an improvement, plus they have two decent drivers in Heikki and Jarno, who know what they're doing, so where are the results?