USB inf for win7 64bit not working and unstable

Hello,

I´m using the INF below for Win 7 64 bit, but it doesn´t work well... When I attach the device, the connections remains unstable and Windows looses the device as If I was removing it. Besides, If I remove the device and attach it again, Device Manager shows it as a com port but with an exclamation point signaling that the Device couldn´t be started (Error Code 10). If I repeat this process removing and reattaching the device after N Trials Windows recognizes it again normally.

Does anyone faced this ? Does this INF really works in Win 7 64 bit environnments ?

;
; Keil - An ARM Company Communication Device Class driver installation file
; (C)2007-2008 Copyright
;

[Version]
Signature="$Windows NT$"
Class=Ports
ClassGuid={4D36E978-E325-11CE-BFC1-08002BE10318}
Provider=%Keil%
;;; LayoutFile=layout.inf ;; not supported in Vista and later
DriverVer =04/14/2008, 5.1.2600.5512
; CatalogFile=mcb2300-vcom.cat

[Manufacturer]
%Keil%=DeviceList,ntamd64

;------------------------------------------------------------------------------
; Device list
;------------------------------------------------------------------------------

[DeviceList]
%DESCRIPTION%=MCB2300USB, USB\VID_c251&PID_1705
%COMPOSITE% =MCB2300USB, USB\VID_FF28&PID_0001&MI_01

[DeviceList.ntamd64]
%DESCRIPTION%=MCB2300USB, USB\VID_c251&PID_1705
%COMPOSITE% =MCB2300USB, USB\VID_FF28&PID_0001&MI_01

;------------------------------------------------------------------------------
; Installation
;------------------------------------------------------------------------------

[SourceDisksNames]
;;; this blank section satisfies chkinf
[SourceDisksFiles]
;;; this blank section satisfies chkinf

[DestinationDirs]
FakeModemCopyFileSection=12
DefaultDestDir = 12

[MCB2300USB]
include=mdmcpq.inf
CopyFiles=FakeModemCopyFileSection
AddReg=MCB2300USB.AddReg

[MCB2300USB.AddReg]
HKR,,DevLoader,,*ntkern
HKR,,NTMPDriver,,usbser.sys
HKR,,EnumPropPages32,,"MsPorts.dll,SerialPortPropPageProvider"

[MCB2300USB.Services]
AddService=usbser, 0x00000002, DriverService

[DriverService]
DisplayName=%DRIVER.SVC%
ServiceType=1
StartType=3
ErrorControl=1
ServiceBinary=%12%\usbser.sys

;------------------------------------------------------------------------------
; String Definitions
;------------------------------------------------------------------------------

[Strings]
Keil = "Keil - An ARM Company"
DRIVER.SVC = "MCB2300 USB VCom Driver"
DESCRIPTION= "MCB2300 USB VCom Port"
COMPOSITE = "MCB2300 MSC-CDC COM Port"