Shimano 10 Speed Woes

I recently purchased a Litespeed Vortex frame, Shimano 10 speed groupo, and a Mavic Ksyrium SL2 wheelset. The "build-up" went fine until I installed the wheels and attempted to adjust the rear derailleur. The wheelset comes with a shim to allow use with Shimano, the 10 speed cassette also has a narrow shim to allow trghe cassete to be used a a standard 8 or 9 speed hub. Problem I'm having is that the derailleur will not shift to the small cog on the SL2's. It seems that if I use both spacers (Mavic and Shimano) I can only move to the second cog. If I take off the Mavic spacer required for Shimano, the cassette is loose. If I use just the Mavic spacer it still will not shift to the small cog. I've taken the cassette and installed it on a Shimano hub on a 9 speed wheel. It shifts to the smallest cog but still doesn't do it without hesitation. Has anyone experienced this? I'm not sure whether the problem is with the SL2 wheel, the derrailer, or with the frame. The hager appears to be "square".