Try rem out the shader call also in the fpe file. I have had up to 5 textures working of 6 so far. This was 3 days ago.
Of coarse no shader effect, but they did not crash the light mapper.
Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz, 2400 Mhz, 4 Core(s), 4 Logical Processor(s), 8gb RAM, Nvidia gtx660, Windows 7 Pro 64bit