ATTiny85 + DHT22 = DHT_BUS_HUNG

[Netspider]

Hi,
I try to use a DHT22 with an ATTiny85 at 8MHz with the internal oscillator and the Arduino 1.0.5 platform. I read every 8 seconds and always get DHT_BUS_HUNG. With a normal Arduino Uno the DHT22 is working fine.
I calibrated the ATTiny85 with TinyTuner so it should be as precise as possible.
Is this a known issue? Can I do something about this? How could I debug this?