diff --git a/src/cnn.c b/src/cnn.c
index de37bc31..ed5fee3c 100644
--- a/src/cnn.c
+++ b/src/cnn.c
@@ -308,7 +308,7 @@ void train_assira()
 
 void train_imagenet()
 {
-	network net = parse_network_cfg("cfg/imagenet_backup_slowest_2340.cfg");
+	network net = parse_network_cfg("cfg/imagenet_small_830.cfg");
     printf("Learning Rate: %g, Momentum: %g, Decay: %g\n", net.learning_rate, net.momentum, net.decay);
     int imgs = 1000/net.batch+1;
 	srand(6472345);
@@ -1016,6 +1016,17 @@ void test_gpu_net()
 
 int main(int argc, char *argv[])
 {
+    int i;
+    int ksize = 3;
+    int stride = 4;
+    int width_col = 20;
+    for(i = 0; i < 10; ++i){
+        int start = (i<ksize)?0:(i-ksize)/stride + 1;
+        int start2 = (i-ksize+stride)/stride;
+        int end = i/stride + 1;
+        end = (width_col < end) ? width_col : end;
+        printf("%d: %d vs %d, %d\n", i, start,start2, end);
+    }
     if(argc != 2){
         fprintf(stderr, "usage: %s <function>\n", argv[0]);
         return 0;
diff --git a/src/col2im.cl b/src/col2im.cl
index 38d7af3c..2ccf89e8 100644
--- a/src/col2im.cl
+++ b/src/col2im.cl
@@ -21,13 +21,15 @@ __kernel void col2im(__global float *data_col, int batch,
     id /= channels;
     int b = id%batch;
 
-    int w_start = (w<ksize)?0:(w-ksize)/stride + 1;
+    //int w_start = (w<ksize)?0:(w-ksize)/stride + 1;
+    int w_start = (w-ksize+stride)/stride;
     int w_end = w/stride + 1;
-    w_end = (width_col < w_end) ? width_col : w_end;
+    //w_end = (width_col < w_end) ? width_col : w_end;
 
-    int h_start = (h<ksize)?0:(h-ksize)/stride+1;
+    int h_start = (h-ksize+stride)/stride;
+    //int h_start = (h-ksize)/stride+1;
     int h_end = h/stride + 1;
-    h_end = (height_col < h_end) ? height_col : h_end;
+    //h_end = (height_col < h_end) ? height_col : h_end;
 
     int rows = channels * ksize * ksize;
     int cols = height_col*width_col;
@@ -39,7 +41,9 @@ __kernel void col2im(__global float *data_col, int batch,
     int h_col, w_col;
     for(h_col = h_start; h_col < h_end; ++h_col){
         for(w_col = w_start; w_col < w_end; ++w_col){
-            val += data_col[offset +h_col*h_coeff + w_col*w_coeff];
+            int col_index = offset +h_col*h_coeff + w_col*w_coeff;
+            float part = (w_col < 0 || h_col < 0 || h_col >= height_col || w_col >= width_col) ? 0 : data_col[col_index];
+            val += part;
         }
     }
     data_im[index] = val;
diff --git a/src/convolutional_layer.c b/src/convolutional_layer.c
index 42f4f219..fee559bb 100644
--- a/src/convolutional_layer.c
+++ b/src/convolutional_layer.c
@@ -336,7 +336,7 @@ void bias_output_gpu(const convolutional_layer layer)
     cl.error = clSetKernelArg(kernel, i++, sizeof(layer.output_cl), (void*) &layer.output_cl);
     check_error(cl);
 
-    const size_t global_size[] = {layer.batch, layer.n*size};
+    const size_t global_size[] = {layer.n*size, layer.batch};
 
     clEnqueueNDRangeKernel(queue, kernel, 2, 0, global_size, 0, 0, 0, 0);
     check_error(cl);
diff --git a/src/convolutional_layer.cl b/src/convolutional_layer.cl
index 6393c37b..92c9d294 100644
--- a/src/convolutional_layer.cl
+++ b/src/convolutional_layer.cl
@@ -1,10 +1,10 @@
 
 __kernel void bias(int n, int size, __global float *biases, __global float *output)
 {
-    int batch = get_global_id(0);
-    int id = get_global_id(1);
+    int id = get_global_id(0);
+    int batch = get_global_id(1);
     int filter = id/size;
-    int position = id%size;
+    //int position = id%size;
 
     output[batch*n*size + id] = biases[filter];
 }