V-USB with ATTiny461

This MCU works great, but I've just used it with a crystal (12MHz) yet. The construction I've used uses zenerdiodes on the D+ and D- lines. I choose this design to secure the frequency, if using two 1N4148's on the +5V-line we're way out of specifikations for the MCU. This goes for the ATTiny25/45/85 as well, but it works most of the times.

As usual I use AVR Studio to set the fuses when hooking up a new MCU. The fuse settings doesn't change when updating the firmware later, so this just has to be done one time.
The fuse settings I use:
Extended: 0xFF
High: 0xD8
Low: 0xFF

USB data is connected to Port B:

#define USB_CFG_IOPORTNAME B
/* This is the port where the USB bus is connected. When you configure it to
* "B", the registers PORTB, PINB and DDRB will be used.
*/
#define USB_CFG_DMINUS_BIT 3
/* This is the bit number in USB_CFG_IOPORT where the USB D- line is connected.
* This may be any bit in the port.
*/
#define USB_CFG_DPLUS_BIT 6