Software Serial with Attiny45 in gibberish

Hello,
I recently started again with Arduino because I really like the Attinys.

However, I strugle with SoftwareSerial:

#include <SoftwareSerial.h>

#define rxPin 3
#define txPin 4

SoftwareSerial debugSerial(rxPin, txPin);

void setup()
{
     pinMode(rxPin, INPUT);
     pinMode(txPin, OUTPUT);

     debugSerial.begin(4800);
}

void loop()
{
     debugSerial.println("a");

     delay(1000);
}

I double checked the baud rate and connections!
But instead of an "a" I recive funny looking o's.

I am using an Arduino Duemilanove for writing my code on the Attiny45.

Thanks in advance
Vedran

--
Edit:

  • 8MHz Attiny
  • Attiny is powered by the 5V rail of the Arduino
  • The same Arduino is used as the Reciver