diff --git a/defaults.lua b/defaults.lua
index 26ec2f5c0..99909d8d1 100644
--- a/defaults.lua
+++ b/defaults.lua
@@ -53,6 +53,9 @@ DSHOWFILESIZE = false
 -- default to true, set to false for counterclockwise rotation
 DLANDSCAPE_CLOCKWISE_ROTATION = true
 
+-- page overlap pixels
+DOVERLAPPIXELS = 30
+
 -- customizable tap zones(rectangles)
 -- x: x coordinate of top left corner in proportion of screen width
 -- y: y coordinate of top left corner in proportion of screen height
diff --git a/frontend/document/document.lua b/frontend/document/document.lua
index e74ad5bc9..c5ec407cc 100644
--- a/frontend/document/document.lua
+++ b/frontend/document/document.lua
@@ -150,9 +150,13 @@ This method returns pagesize if bbox is corrupted
 --]]
 function Document:getUsedBBoxDimensions(pageno, zoom, rotation)
 	local bbox = self:getPageBBox(pageno)
+	-- clipping page bbox
+	if bbox.x0 < 0 then bbox.x0 = 0 end
+	if bbox.y0 < 0 then bbox.y0 = 0 end
+	if bbox.x1 < 0 then bbox.x1 = 0 end
+	if bbox.y1 < 0 then bbox.y1 = 0 end
 	local ubbox_dimen = nil
-	if (bbox.x0 < 0) or (bbox.y0 < 0) or (bbox.x1 < 0) or (bbox.y1 < 0)
-	or (bbox.x0 == bbox.x1) or (bbox.y0 == bbox.y1) then
+	if (bbox.x0 > bbox.x1) or (bbox.y0 > bbox.y1) then
 		-- if document's bbox info is corrupted, we use the page size
 		ubbox_dimen = self:getPageDimensions(pageno, zoom, rotation)
 	else
diff --git a/frontend/ui/reader/readerpaging.lua b/frontend/ui/reader/readerpaging.lua
index 56b5dbc1c..48d7f48a7 100644
--- a/frontend/ui/reader/readerpaging.lua
+++ b/frontend/ui/reader/readerpaging.lua
@@ -17,7 +17,7 @@ local ReaderPaging = InputContainer:new{
 	visible_area = nil,
 	page_area = nil,
 	show_overlap_enable = nil,
-	overlap = Screen:scaleByDPI(30),
+	overlap = Screen:scaleByDPI(DOVERLAPPIXELS),
 	
 	page_flipping_mode = false,
 	bookmark_flipping_mode = false,
@@ -400,8 +400,9 @@ function ReaderPaging:getTopPage()
 end
 
 function ReaderPaging:onInitScrollPageStates(orig)
+	--DEBUG.traceback()
 	DEBUG("init scroll page states", orig)
-	if self.view.page_scroll then
+	if self.view.page_scroll and self.view.state.page then
 		self.orig_page = self.current_page
 		self.view.page_states = {}
 		local blank_area = Geom:new{}
@@ -734,6 +735,7 @@ end
 
 -- wrapper for bounds checking
 function ReaderPaging:gotoPage(number, orig)
+	--DEBUG.traceback()
 	if number == self.current_page or not number then
 		return true
 	end
diff --git a/frontend/ui/readerui.lua b/frontend/ui/readerui.lua
index 95ab3d1ea..d40be38de 100644
--- a/frontend/ui/readerui.lua
+++ b/frontend/ui/readerui.lua
@@ -176,36 +176,36 @@ function ReaderUI:init()
 	end
 	-- for page specific controller
 	if self.document.info.has_pages then
-		-- if needed, insert a paging container
-		table.insert(self, ReaderPaging:new{
+		-- cropping controller
+		table.insert(self, ReaderCropping:new{
 			dialog = self.dialog,
 			view = self[1],
-			ui = self
+			ui = self,
+			document = self.document,
 		})
 		-- zooming controller
-		self.zoom = ReaderZooming:new{
+		local zoom = ReaderZooming:new{
 			dialog = self.dialog,
 			view = self[1],
 			ui = self
 		}
-		table.insert(self, self.zoom) -- hold reference to zoom controller
-		-- panning controller
-		table.insert(self, ReaderPanning:new{
+		table.insert(self, zoom)
+		-- paging controller
+		table.insert(self, ReaderPaging:new{
 			dialog = self.dialog,
 			view = self[1],
 			ui = self
 		})
-		-- cropping controller
-		table.insert(self, ReaderCropping:new{
+		-- panning controller
+		table.insert(self, ReaderPanning:new{
 			dialog = self.dialog,
 			view = self[1],
-			ui = self,
-			document = self.document,
+			ui = self
 		})
 		-- hinting controller
 		table.insert(self, ReaderHinting:new{
 			dialog = self.dialog,
-			zoom = self.zoom,
+			zoom = zoom,
 			view = self[1],
 			ui = self,
 			document = self.document,
diff --git a/koreader-base b/koreader-base
index cf62f2108..1ef0dee5c 160000
--- a/koreader-base
+++ b/koreader-base
@@ -1 +1 @@
-Subproject commit cf62f21087d511c2e9e4e852c2b4402a99bbdcfb
+Subproject commit 1ef0dee5c0dbbbe812b8b5292c5a053f5d88fdcf