USB CDC descriptor problem

Hello.

First of all, I want to say that I don't know if this is the right forum to do the question, but after days searching in the web, reading papers and changing the code, I'll try to explain my dude here.

I'm programming a device, with a USB communication in order to communicate with PC. I use an ATmega1281 with MAX3420 as USB controller. I get the windows recognize the device as COM Port...but I can only send or only receive data. If I try to set number of endpoints to 2 in the Data Class Interface descriptor, windows return an error (code 10), and can't initialize the device.
Here I show the configuration descriptors I use. Thank you for your time in advance! and regards.

const unsigned char CD[]=
// CONFIGURATION Descriptor
{ 0x09,// bLength
0x02,// bDescriptorType = Config
67,0x00,// wTotalLength(L/H)
0x02,// bNumInterfaces = 2
0x01,// bConfigValue
0x00,// iConfiguration
0xC0,// bmAttributes. b7=1
0x32,// MaxPower is 100 ma

// INTERFACE Descriptor
0x09,// length = 9
0x04,// type = IF
0x00,// InterFace Number = 0
0x00,// bAlternate Setting
0x01,// bNum Endpoints = 1 IN
0x02,// bInterfaceClass = 2 Communication
0x02,// bInterfaceSubClass = 2
0x01,// bInterfaceProtocol =1 (SubClass ACM,V.25ter)
0x00,// iInterface
// Header Functional Descriptor (marks beginning of the concatenated set of Functional Descriptors)
0x05,// bFunctionLength, Descriptor size in bytes
0x24,// bDescriptorType, CS_INTERFACE
0x00,// bDescriptorSubtype, Header Functional Descriptor
0x10,0x01,// bcdCDC

// Abstract Control Management Functional Descriptor
0x04,// bDescriptorLength, Descriptor size in bytes
0x24,// bDescriptorType, CS_INTERFACE
0x02,// bDescriptorSubtype, ACM Functional Descriptor
0x06,// bmCapabilities

// Union Functional Descriptor
0x05,// bFunctionLength, Descriptor size in bytes
0x24,// bDescriptorType, CS_INTERFACE
0x06,// bDescriptorSubtype, Union Functional Descriptor
0x00,// bMasterInterface
0x01,// bSlaveInterface0

// Call Management Functional Descriptor
0x05,// bFunctionLength, Descriptor size in bytes
0x24,// bDescriptorType, CS_INTERFACE
0x01,// bDescriptorSubtype, Call Management Funct.Desc.
0x03,// bmCapabilities
0x01,// bDataInterface

// Endpoint Descriptor EP3-IN
0x07,// bLength
0x05,// bDescriptorType (Endpoint)
0x83,// bEndpointAddress (EP3 IN)
0x03,// bmAttributes (interrupt = 3)
0x40,0x00,// wMaxPacketSize
0x02,// bInterval, Maximum latency

// INTERFACE Descriptor
0x09,// length = 9
0x04,// type = IF
0x01,// InterFace Number = 1
0x00,// bAlternate Setting
0x01,// bNum Endpoints = 2 (IN&OUT)
0x0A,// bInterfaceClass = A (Data)
0x00,0x00,// bInterfaceSubClass, bInterfaceProtocol
0x00,// iInterface

// Endpoint Descriptor EP2-IN
0x07,// bLength
0x05,// bDescriptorType (Endpoint)
0x82,// bEndpointAddress (EP2-IN)
0x02,// bmAttributes (bulk = 2)
0x40,0x00,// wMaxPacketSize (64[0x40])
0x00,// bInterval

// Endpoint Descriptor EP1-OUT
0x07,// bLength
0x05,// bDescriptorType (Endpoint)
0x01,// bEndpointAddress (EP1-OUT)
0x02,// bmAttributes (bulk = 2)
0x40,0x00, // wMaxPacketSize (64[0x40])
0x00,// bInterval
};