LPC932 and I2C - who can help?

[George]

Hi associates!

Using the 932 for quite a while in different applications, I thought I would know all of the kinks of this part. So I started a project where I intented to use the 932 as a receive-only I2C-Slave in a single master environment.

Topology:
uPSD3243 as a master,
several PCA9555 as slaves
some other I2C busmembers for different purposes,
alltogether approx. nine I2C-Slaves and 200kcs busclock.

So far, so good, the system works fine.

Adding the 932 as a new member is where trouble starts.
I downloaded the code architect template and added the callback functions.

And:
the 932 recognizes his address(W) and acknowledges it. (Status 0x60)
The next databyte is not acknowledged,  the status shows 0x00. I trapped this state, mirroring the status on P2.

Inspections with a logic analyzer did prove that behaviour.

Does anyone in this group knows anything about an undiscovered flaw in the silicon of that part, or, can anyone provide a skeleton program which is running as a read-only slave so I might find my mistake?

Thank you so much in advance! It's embarrassing spending nights over this issue.

George