Latest update - I have turned AirPrint back on, and disabled RAW/LPR/IPP. No further Exception Reports so far.
I'm seeing the same issue on my 3260 and I'm using the latest firmware, v3.50.02.01. I just turned off RAW/LPR/IPP as suggested and hopefully that fixes it.
It turns out that IPP is required for AirPrint to work, so I can't leave that disabled. I re-enabled it (but left Raw/LPR disabled) and the exception reports have started printing again, so it's definitely an IPP problem.