i tried with your example file, changed the 5 small pictures by bigger ones, 256x256 in greyscale, but after that, the 3d model has no more reflection :s, ok "SOLVED" the problem come when the reflection map is not a perfect square maybe something to correct???
if the map is not 256x256 or 512x512 etc, but 256x1000 then, the reflection map don't work at all