diff --git a/backend/genesys.c b/backend/genesys.c
index 3dc7ef5e2..1e444647f 100644
--- a/backend/genesys.c
+++ b/backend/genesys.c
@@ -1733,7 +1733,9 @@ sanei_genesys_search_reference_point (Genesys_Device * dev, uint8_t * data,
   if ((dev->model->ccd_type == CCD_HP2300
        && dev->model->motor_type == MOTOR_HP2300)
       || (dev->model->ccd_type == CCD_HP2400
-	  && dev->model->motor_type == MOTOR_HP2400))
+	  && dev->model->motor_type == MOTOR_HP2400)
+      || (dev->model->ccd_type == CCD_HP3670
+	  && dev->model->motor_type == MOTOR_HP3670))
     {
       top = 0;
       count = 0;
diff --git a/backend/genesys_devices.c b/backend/genesys_devices.c
index 03523e020..fd331f914 100644
--- a/backend/genesys_devices.c
+++ b/backend/genesys_devices.c
@@ -981,6 +981,7 @@ Genesys_Model hp2400c_model = {
     | GENESYS_FLAG_SKIP_WARMUP
     | GENESYS_FLAG_STAGGERED_LINE
     | GENESYS_FLAG_CUSTOM_GAMMA,
+  GENESYS_HAS_COPY_SW | GENESYS_HAS_EMAIL_SW | GENESYS_HAS_SCAN_SW,
   20,
   132
 };
@@ -1086,7 +1087,7 @@ static Genesys_Model hp3670c_model = {
     | GENESYS_FLAG_XPA
     | GENESYS_FLAG_DARK_CALIBRATION
     | GENESYS_FLAG_OFFSET_CALIBRATION
-    | GENESYS_FLAG_SKIP_WARMUP
+    /* | GENESYS_FLAG_SKIP_WARMUP */
     | GENESYS_FLAG_STAGGERED_LINE
     | GENESYS_FLAG_CUSTOM_GAMMA,
   GENESYS_HAS_COPY_SW | GENESYS_HAS_EMAIL_SW | GENESYS_HAS_SCAN_SW,
diff --git a/backend/genesys_gl646.c b/backend/genesys_gl646.c
index 37fcd4d4e..4130429c9 100644
--- a/backend/genesys_gl646.c
+++ b/backend/genesys_gl646.c
@@ -4439,8 +4439,10 @@ gl646_init_regs_for_warmup (Genesys_Device * dev,
   /* we are not going to move, so clear these bits */
   dev->reg[reg_0x02].value &= ~(REG02_FASTFED | REG02_AGOHOME);
 
-  /* don't enable gamma correction for this scan */
-  dev->reg[reg_0x05].value &= ~REG05_GMMENB;
+  /* don't enable any correction for this scan */
+  dev->reg[reg_0x01].value &= ~REG01_DVDSET;
+  /* XXX STEF XXX
+  dev->reg[reg_0x05].value &= ~REG05_GMMENB; */
 
   /* turn off motor during this scan */
   gl646_set_motor_power (local_reg, SANE_FALSE);
@@ -5304,7 +5306,7 @@ gl646_is_compatible_calibration (Genesys_Device * dev,
        for_overwrite);
 
   /* calibration caching not supported yet for HP3670 */
-  if (cache == NULL || dev->model->ccd_type == CCD_HP3670 || dev->model->ccd_type == CCD_HP2400)
+  if (cache == NULL || dev->model->ccd_type == CCD_HP2400)
     return SANE_STATUS_UNSUPPORTED;
 
   /* build minimal current_setup for calibration cache use only, it will be better