diff --git a/pypulseq/add_gradients.py b/pypulseq/add_gradients.py
index bc273bd9..d1f81064 100644
--- a/pypulseq/add_gradients.py
+++ b/pypulseq/add_gradients.py
@@ -102,7 +102,7 @@ def add_gradients(
             else:
                 times.extend(g.delay + g.tt)
 
-        times = np.sort(np.unique(times))
+        times = np.unique(times)
         dt = times[1:] - times[:-1]
         ieps = np.flatnonzero(dt < eps)
         if np.any(ieps):
@@ -140,7 +140,7 @@ def add_gradients(
             if abs(waveform[0]) > eps and tt[0] > eps:
                 tt[0] += eps
 
-            amplitudes += np.interp(xp=tt, fp=waveform, x=times)
+            amplitudes += np.interp(xp=tt, fp=waveform, x=times, left=0, right=0)
 
         grad = make_extended_trapezoid(
             channel=channel, amplitudes=amplitudes, times=times, system=system
diff --git a/pypulseq/event_lib.py b/pypulseq/event_lib.py
index bf300ded..2d056244 100755
--- a/pypulseq/event_lib.py
+++ b/pypulseq/event_lib.py
@@ -219,7 +219,12 @@ def update(
         data_type : str, default=str()
         """
         if key_id in self.data:
-            del self.keymap[self.data[key_id]]
+            # TODO: When reading a sequence file we can end up with duplicate
+            #       events due to rounding to 6 digits. update() calls to both
+            #       duplicates would give a key error here on the second
+            #       duplicate. Ideally no duplicates should exist though...
+            if self.data[key_id] in self.keymap:
+                del self.keymap[self.data[key_id]]
 
         self.insert(key_id, new_data, data_type)
 
diff --git a/pypulseq/make_extended_trapezoid.py b/pypulseq/make_extended_trapezoid.py
index f460ce75..17effb7e 100644
--- a/pypulseq/make_extended_trapezoid.py
+++ b/pypulseq/make_extended_trapezoid.py
@@ -136,9 +136,8 @@ def make_extended_trapezoid(
             round(times[0] / system.grad_raster_time) * system.grad_raster_time
         )
         grad.tt = times - grad.delay
-        grad.shape_dur = (
-            round(times[-1] / system.grad_raster_time) * system.grad_raster_time
-        )
+        grad.shape_dur = grad.tt[-1]
+        grad.area = 0.5 * ((grad.tt[1:] - grad.tt[:-1]) * (grad.waveform[1:] + grad.waveform[:-1])).sum()
 
     grad.first = amplitudes[0]
     grad.last = amplitudes[-1]
diff --git a/pypulseq/opts.py b/pypulseq/opts.py
index 70028958..0274ad5a 100755
--- a/pypulseq/opts.py
+++ b/pypulseq/opts.py
@@ -82,14 +82,14 @@ def __init__(
 
         if max_grad != None:
             max_grad = convert(
-                from_value=max_grad, from_unit=grad_unit, to_unit="Hz/m", gamma=gamma
+                from_value=max_grad, from_unit=grad_unit, to_unit="Hz/m", gamma=abs(gamma)
             )
         else:
             max_grad = Opts.default.max_grad
 
         if max_slew != None:
             max_slew = convert(
-                from_value=max_slew, from_unit=slew_unit, to_unit="Hz/m", gamma=gamma
+                from_value=max_slew, from_unit=slew_unit, to_unit="Hz/m", gamma=abs(gamma)
             )
         else:
             max_slew = Opts.default.max_slew