diff --git a/piker/ui/_cursor.py b/piker/ui/_cursor.py
index d0f642e4..f6f8edde 100644
--- a/piker/ui/_cursor.py
+++ b/piker/ui/_cursor.py
@@ -109,11 +109,12 @@ class LineDot(pg.CurvePoint):
         # first = self._plot._arrays['ohlc'][0]['index']
         # first = x[0]
         # i = index - first
-        i = index - x[0]
-        if i > 0 and i < len(y):
-            newPos = (index, y[i])
-            QtWidgets.QGraphicsItem.setPos(self, *newPos)
-            return True
+        if index:
+            i = index - x[0]
+            if i > 0 and i < len(y):
+                newPos = (index, y[i])
+                QtWidgets.QGraphicsItem.setPos(self, *newPos)
+                return True
 
         return False
 
diff --git a/piker/ui/_forms.py b/piker/ui/_forms.py
index 6406a199..1f1a7cd5 100644
--- a/piker/ui/_forms.py
+++ b/piker/ui/_forms.py
@@ -105,7 +105,7 @@ class Edit(QLineEdit):
         # TODO: somehow this math ain't right?
         chars_w_pxs = dpi_font.boundingRect('0'*self._chars).width()
         scale = round(dpi_font.scale())
-        psh.setWidth(chars_w_pxs * scale)
+        psh.setWidth(int(chars_w_pxs * scale))
         return psh
 
     def set_width_in_chars(
@@ -218,7 +218,7 @@ class Selection(QComboBox):
 
     ) -> None:
         br = _font.boundingRect(str(char))
-        _, h = br.width(), br.height()
+        _, h = br.width(), int(br.height())
 
         # TODO: something better then this monkey patch
         view = self.view()
@@ -330,7 +330,7 @@ class FieldsForm(QWidget):
         self.form.setSpacing(0)
         self.form.setHorizontalSpacing(0)
 
-        self.vbox.addLayout(self.form, stretch=1/3)
+        self.vbox.addLayout(self.form, stretch=3)
 
         self.labels: dict[str, QLabel] = {}
         self.fields: dict[str, QWidget] = {}
@@ -557,8 +557,8 @@ class FillStatusBar(QProgressBar):
         self.font_size = font_size
 
         self.setFormat('')  # label format
-        self.setMinimumWidth(width_px)
-        self.setMaximumWidth(width_px)
+        self.setMinimumWidth(int(width_px))
+        self.setMaximumWidth(int(width_px))
 
     def set_slots(
         self,
@@ -573,7 +573,7 @@ class FillStatusBar(QProgressBar):
             approx_h,
             slots,
         )
-        clipped = slots * tot_slot_h + 2*self.border_px
+        clipped = int(slots * tot_slot_h + 2*self.border_px)
         self.setMaximumHeight(clipped)
         slot_height_px = tot_slot_h - 2*self.slot_margin_px
 
@@ -657,14 +657,14 @@ def mk_fill_status_bar(
     )
     # size according to dpi scaled fonted contents to avoid
     # resizes on magnitude changes (eg. 9 -> 10 %)
-    min_w = _font.boundingRect('1000.0M% pnl').width()
+    min_w = int(_font.boundingRect('1000.0M% pnl').width())
     left_label.setMinimumWidth(min_w)
     left_label.resize(
         min_w,
         left_label.size().height(),
     )
 
-    bar_labels_lhs.addSpacing(5/8 * bar_h)
+    bar_labels_lhs.addSpacing(int(5/8 * bar_h))
 
     bar_labels_lhs.addWidget(
         left_label,
@@ -796,7 +796,7 @@ def mk_order_pane_layout(
     form.top_label = top_label
 
     # add pp fill bar + spacing
-    vbox.addLayout(hbox, stretch=1/3)
+    vbox.addLayout(hbox, stretch=3)
 
     # TODO: handle resize events and appropriately scale this
     # to the sidepane height?
diff --git a/piker/ui/_l1.py b/piker/ui/_l1.py
index 0ff264bc..bfa0551e 100644
--- a/piker/ui/_l1.py
+++ b/piker/ui/_l1.py
@@ -199,7 +199,14 @@ class LevelLabel(YAxisLabel):
         elif self._orient_v == 'top':
             lp, rp = rect.bottomLeft(), rect.bottomRight()
 
-        p.drawLine(lp.x(), lp.y(), rp.x(), rp.y())
+        p.drawLine(
+            *map(int, [
+                lp.x(),
+                lp.y(),
+                rp.x(),
+                rp.y(),
+            ])
+        )
 
     def highlight(self, pen) -> None:
         self._pen = pen
diff --git a/piker/ui/_style.py b/piker/ui/_style.py
index 6ba3b76a..b51331ab 100644
--- a/piker/ui/_style.py
+++ b/piker/ui/_style.py
@@ -142,8 +142,8 @@ class DpiAwareFont:
         self._font_inches = inches
         font_size = math.floor(inches * dpi)
 
-        log.info(
-            f"screen:{screen.name()}]\n"
+        log.debug(
+            f"screen:{screen.name()}\n"
             f"pDPI: {pdpi}, lDPI: {ldpi}, scale: {scale}\n"
             f"\nOur best guess font size is {font_size}\n"
         )
diff --git a/piker/ui/order_mode.py b/piker/ui/order_mode.py
index 48be0384..6795f384 100644
--- a/piker/ui/order_mode.py
+++ b/piker/ui/order_mode.py
@@ -671,7 +671,9 @@ async def open_order_mode(
             form.fill_bar.height()
             # feed_label.height()
         )
-        vbox.setSpacing((1 + 5/8)*_font.px_size)
+        vbox.setSpacing(
+            int((1 + 5/8)*_font.px_size)
+        )
 
         # fill in brokerd feed info
         host, port = feed.portal.channel.raddr
diff --git a/setup.py b/setup.py
index ebd034fa..6f8fd898 100755
--- a/setup.py
+++ b/setup.py
@@ -52,6 +52,7 @@ setup(
         'trio',
         'trio-websocket',
         # 'tractor',  # from github currently
+        'msgspec',  # performant IPC messaging
         'async_generator',
 
         # brokers
@@ -87,6 +88,7 @@ setup(
         "Programming Language :: Python :: Implementation :: CPython",
         "Programming Language :: Python :: 3 :: Only",
         "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
         'Intended Audience :: Financial and Insurance Industry',
         'Intended Audience :: Science/Research',
         'Intended Audience :: Developers',