:idea:
For my serial work on PICs (i know you are using an atmel, but it may help others...) I just use a 10k resistor to the RX pin (on the PIC) and connect the TX (from the PIC) straight to the PC.
The catch.... you can't use the UART, the rs232 data is now "inverted", all the max232 ic's etc invert the data for use with the PIC UART...
It works a treat, i have used this reliably (over standard cable lengths) to 115200 at 8mhz
Let me know if anyone wants the code for the serial tx/rx!