diff --git a/device/win_usb/win_usb.cpp b/device/win_usb/win_usb.cpp
index f3af35d..567bf25 100644
--- a/device/win_usb/win_usb.cpp
+++ b/device/win_usb/win_usb.cpp
@@ -719,14 +719,14 @@ int usb_device::transfer_control(uint8_t type, uint8_t req, uint16_t val, uint16
         }
         else
         {
-            //io = GetLastError();
-            //if (io == ERROR_ACCESS_DENIED)
-            //    ret = LIBUSB_ERROR_ACCESS;
-            //else if (io == ERROR_SEM_TIMEOUT)
-            //    ret = LIBUSB_ERROR_TIMEOUT;
-            //else
-            //    ret = LIBUSB_ERROR_PIPE;
-            ret = 0;
+            io = GetLastError();
+            if (io == ERROR_ACCESS_DENIED)
+                ret = LIBUSB_ERROR_ACCESS;
+            else if (io == ERROR_SEM_TIMEOUT)
+                ret = LIBUSB_ERROR_TIMEOUT;
+            else
+                ret = LIBUSB_ERROR_PIPE;
+            // ret = 0;
         }
         oc->release();
     }
diff --git a/sane/DlgPage.cpp b/sane/DlgPage.cpp
index 6d688cb..2aac5f6 100644
--- a/sane/DlgPage.cpp
+++ b/sane/DlgPage.cpp
@@ -7,7 +7,7 @@
 #include "DlgArea.h"
 #include "DlgGamma.h"
 #include "gb_json.h"
-
+#include "../../code_device/hgsane/sane_hg_mdw.h"	// for 
 
 // #pragma comment(linker,"\"/manifestdependency:type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*'\"")
 
@@ -1080,6 +1080,7 @@ void dlg_page::control_action(HWND wnd)
 		if (val)
 		{
 			SANE_Int	after = 0;
+			std::string	to_v(hg_sane_middleware::option_value_2_string(type, val));
 			SANE_Status	statu = sane_.sane_control_option_api(dev_, id - dlg_page::dyn_id_base, SANE_ACTION_SET_VALUE, val, &after);
 			gb::sane_config_schm* cfg = get_config();
 			done_ = false;
@@ -1106,7 +1107,24 @@ void dlg_page::control_action(HWND wnd)
 				if (len)
 					cfg->config_changed(id - dlg_page::dyn_id_base, (char*)val, len);
 			}
-			set_ctrl_value(wnd, type, val, false, !(after || statu));
+			if (statu == SANE_STATUS_INVAL)
+			{
+				std::wstring attr(L"\u6B64\u8BBE\u5907\u4E0D\u652F\u6301\u5C06 \u201C" + local_trans::a2u(sane_.sane_get_option_descriptor_api(dev_, id - dlg_page::dyn_id_base)->title, CP_UTF8) + L"\u201D \u8BBE\u7F6E\u4E3A\uFF1A"),
+							 attr_v(local_trans::a2u(to_v.c_str(), CP_UTF8));
+				MessageBoxW(hwnd(), (attr + attr_v).c_str(), L"\u53C2\u6570\u9519\u8BEF", MB_OK);
+				set_ctrl_value(wnd, type, val, true);
+			}
+			else
+			{
+				std::string tov(hg_sane_middleware::option_value_2_string(type, val));
+				if (tov != to_v)
+				{
+					std::wstring attr(L"\u539F\u53C2\u6570 \u201C" + local_trans::a2u(to_v.c_str(), CP_UTF8) + L"\u201D \u4E0D\u7CBE\u786E\u6216\u8BBE\u5907\u4E0D\u652F\u6301\uFF0C\u5DF2\u8C03\u6574\u4E3A\uFF1A"),
+								 attr_v(local_trans::a2u(tov.c_str(), CP_UTF8));
+					MessageBoxW(hwnd(), (attr + attr_v).c_str(), L"\u53C2\u6570\u8C03\u6574", MB_OK);
+				}
+				set_ctrl_value(wnd, type, val, false, !(after || statu));
+			}
 			done_ = true;
 			if (id == dlg_page::dyn_id_base + id_dpi_)
 			{
@@ -1118,7 +1136,7 @@ void dlg_page::control_action(HWND wnd)
 			else if (id == dlg_page::dyn_id_base + id_paper_)
 				paper_ = local_trans::a2u((char*)val, CP_UTF8);
 
-			if (after || statu)
+			if (after || (statu && statu != SANE_STATUS_INVAL))
 				PostMessage(parent_, WM_REFRESH_OPTION, id - dlg_page::dyn_id_base, 0);
 			free_ctrl_value(val);
 		}
diff --git a/sane/scanner.cpp b/sane/scanner.cpp
index 4544745..7cb40ee 100644
--- a/sane/scanner.cpp
+++ b/sane/scanner.cpp
@@ -348,8 +348,8 @@ scanner::scanner(SCANNERID id) : handle_(NULL), id_(id), ex_id_(EXTENSION_ID_BAS
 	int mem_limit = GetPrivateProfileIntW(L"mem", L"max_img", 0, (cfg_path_ + L"debug.cfg").c_str());
 	if (mem_limit > 0)
 	{
-		// this value is used for driver usb image queue, here should multiple 5
-		max_img_mem_ = 5 * mem_limit;
+		// this value is same as driver memory limit ...
+		max_img_mem_ = mem_limit;
 	}
 	err_ = open();
 }