Hi Uwe,
<halfknowledge> Isn't the at91 i2c hardware broken or unreliable suchthat it's usually recommended to stick to i2c-gpio? If so maybe the sameapplies to client mode and someone should better extend i2c-gpio to handle the slave API?
Can you describe what kind of unreliability you've observed? I had the master and slave mode running for some time and it seems to work quite well. No data losses. No undesired states.
Best regards, Juergen