Problem with size of structers

Hi anybody

I declare the folowing stuctures:

typedef struct {
    ubyte	bLength;
    ubyte	bDescriptorType;
    ubyte	bInterfaceNumber;
    ubyte	bAlternateSetting;
    ubyte	bNumEndpoints;
    ubyte	bInterfaceClass;
    ubyte	bInterfaceSubClass;
    ubyte	bInterfaceProtocol;
    ubyte	iInterface;
} USB_interface_desc_t;

typedef struct {
    ubyte	bLength;
    ubyte	bDescriptorType;
    uword	wTotalLength;
    ubyte	bNumInterfaces;
    ubyte	bConfigurationValue;
    ubyte	iConfiguration;
    ubyte	bmAttributes;
    ubyte	MaxPower;
} USB_config_desc_t;


typedef struct {
    ubyte	bLength;
    ubyte	bDescriptorType;
    struct {
	ubyte address:4;
	ubyte reserved:3;
	ubyte direction:1;
    } bEndpointAddress;
    ubyte	bmAttributes;
    uword	wMaxPacketSize;
    ubyte	bInterval;
} USB_endpoint_desc_t;

typedef struct {
    USB_config_desc_t	usb_dev_config_desc;
    USB_interface_desc_t	usb_interface_0_alt_0_desc;
    USB_endpoint_desc_t	usb_dev_endpoint_alt_0_desc[2];
} USB_long_config_desc_t;