Spatial Analyst projection output

Discussion created by msiwek on May 17, 2010
I'm generating a total cost surface for a least cost model.  When I input my eight layers into raster calculator I receive the warning

"Your raster data will be projected to another coordiante system to perform the requested analysis.  This can be slow and induce error in your result, particularly for large geographic areas and at high latitudes.  Would you like to continue?"

Why am I receiving this warning, all of my layers are projected to the same coordinate system so there seems to be no conflict.  When I do a smaller equation with only two of any of my eight themes this warning does not come up.  Should I be concerned about this warning?  Raster Calculator outputs my total cost surface and it appears to be in the correct coordinate system.