Problem reagarding the tiff and shape file projections

I have a tiff file that is in WGS84. First of all I opened it in a new map. Now I created a new layer(shape, polygon) around this tiff layer(with same projection WGS84). Now when I changed the projection of the map to EPSG:32617(UTM 17N) then the two layers are rendering differently. It seems there is some problem with the raster rendering in geotools. PFA snapshots for your consideration. Please help in this regard. I went thru the geotools gt.renderer and found a class "Crop". I think this is generating the wrong information. I debugged the code and found that for an input envelope [-117.769582129, 33.611401899, -117.602787889, 33.749013675], the renderer returns [-117.75980902900001, 33.611401899, -117.602787889, 33.749013675] (in preSample Object). For a small area this is a very big difference.